Hmm, so let me try and put this in some different terms and maybe things might be clearer for me. Please correct me if I'm mistaken on something.
Define "have a solution for": Let me use examples here, over the course of the game, you're not going to be able to cut it with just two guys on Agriculture; you consume more food and your dudes cost more. One solution is to generate more food by upgrading your food techs and/or putting more guys on them. Another solution is to build Ocean Liner Service. Another solution is to get extra yellow dots. Maybe another solution is to get lots of yellow cards but I don't think that's really all that viable. "Have a solution for" food means you have at least one of these things (or any other one I forgot)
I think that it's very rare that you'll get away with no extra food production. 3 food per turn plus something like Ocean Liner Service/extra yellow tokens might just take you through, but that's a pretty rare set of circumstances (OLS is an age II wonder... what are you doing until then?). I think that a good benchmark minimum to aim for is (effectively) 4 food production per turn. So e.g. 2 guys in Irrigation (Age I food tech) will do that, OLS will kinda do that, lots of extra yellow tokens might just do that, you get the idea. And I said minimum, because that's probably not quite enough most of the time. If I win a nice yellow token territory, 2 Irrigation guys is often enough, but if not, then I'd often want a third or perhaps to grab Selective Breeding/Mechanised Agriculture.
Rock: You can upgrade your rock techs and/or put more guys on rock production. You can get more civil actions and take more yellow cards. You can research certain blue techs that decrease your need for rock; maybe that means an abundance of science? Is there really anything else here? Will military strength sufficiently compensate for this?
I think that, far more than any other resource, rocks are the easiest thing to substitute. There are loads of action cards which give extra bonuses to resouce production - Mineral Deposts (produce X), Ideal Building Site (build a building for -X), Efficient Upgrade (upgrade for -X), Patriotism (+X for military and 1 MA), Engineering Genius (build wonder stage for X+1 less), Rich Land (build mine or farm for -X) and some specialised ones giving resources for military. X is the age you're in plus 1 in each of these. Oh and a lot of those have multiples in each age. That's... actually a surprising amount of the deck which is just cards giving extra resources. If you don't get a resource tech, then taking one of these per turn gives you effectively around 2-4 extra resources per turn, at the cost of some CAs per turn. There's also the other things you mention - construction techs to reduce costs, military to take opponent's resources (this one is mega unreliable of course though), also events give rocks not too infrequently etc.
Science: You can upgrade your science techs and build up to your Urban Building Limit on all of the stuff that gives you light bulbs. You can take leaders that provide extra science per turn. A temporary fix is to revolt to a new government when it comes time and save the science cost that way. Really, it seems like any opportunity to get more light bulbs is something that's worth investing in, right?
Science is pretty tough to get extra of, you pretty much need to get a science tech in age I or II. Fortunately there are a decent number of those in the decks, so especially in 2 player you should be able to get one, but there's always a chance you won't. There aren't many science providing actions, but they do tend to give a lot each.
Happiness: You can upgrade your temples/arenas and get more happies that way (more than one happy per dude), you can just make a lot of dudes and have half of them be discontent (probably not such a great idea long-term), you can get more yellow dots to decrease your need for happiness, you can build a wonder or get a territory that provides enough happies until in the endgame you're building Theaters with all your guys anyways (living with one happy per dude).
I dunno if I'd say endgame Theaters is something that happens THAT frequently, but otherwise, agreement here more or less. I would say it's uncommon to go the entire game without a happiness tech, although if you get a few extra happy faces you can manage it (I think I did that once). I think I normally grab a happiness tech in age II, sometimes in age I though. Which one is usually just whichever is there when I need it.
Military: Uhh, get lots of defense cards and hope war isn't declared on you? I've heard the school of thought that you don't have to actually build up your military to defend yourself, you just have to be able to build up your military next turn if you have to and that's usually sufficient, but I haven't had much success with this. I mean researching military techs can only get you so far, it seems the only "have a solution for" available here is to research better military techs and put lots of guys on them. Is there anything else here?
Military is something I just don't think you can reliably skip. Sometimes you can luck out and have low strength but no-one else can draw a war (or only other relatively weak players), or maybe nobody goes military (but in that case if you had gone military chances are things would have worked out better for you). But usually, I think you need some strength on the board.
Civil Actions: It's clear to me that four civil actions isn't enough for the game, you need to get more. I don't know that there's a substitute for this other than just to get more white dots however you can. How many CAs do you need to "have a solution" for Civil Actions? This assumes you aren't using an abundance of CAs to cover up for another problem you might have.
I think 6 CAs is enough that you can do what you need without serious issue, but I would generally prefer to have 7 or so. More is obviously better, but obviously, each extra CA you get will have a cost of some form, be it a played leader in lieu of a different leader, a wonder that cost resources, a tech which cost science to play etc. and those costs might have gone towards something else. I guess what that means is, if I get Constitutional Monarchy, I'd like one more CA, but if I get Republic, I won't care too much. And well often it's actually the other way around, I have an extra CA so Const Mon appeals more etc. If really necessary, I feel like you could probably get by with only 5 CAs.
Military Actions: Yeah you need 3 or 4 of these eventually.
ASAP I would say. Warfare is a tech I very often take for 1 CA and will consider at 2 CAs. Getting a good tactics card can make a big difference, as can better event and aggression control.
Points: I realize that these are the point of the game (see what I did there?) but I would hope these are just a metric to show you how well you did at all this other stuff. Otherwise, why are they there? So I don't necessarily think that this discussion applies here.
Yeah, kinda. Culture does sometimes matter earlier in the game (e.g. Terrorism event, National Pride event), but it's more kind of, you can sacrifice some tempo to score good points earlier on in the game, and that can sometimes be a good thing and sometimes a bad thing. E.g. Libraries compared to Labs, Theaters in general. Usually though, everything kind of comes down to 'how will my strengths score me points/how will my weaknesses prevent me scoring?'
So the theory here is that one must "have a solution for" all of these things if they want to have a chance to win the game. Some of them have limited options for how you do it, but other ones can be made up for by excelling in other areas and are more flexible. Does that sound reasonable?
Hmm... I'm not quite sure how to respond to this but let me put it this way: If you sit with only three resource income per turn, and never take action cards, what's going to happen? If I sit with just two guys on Philosophy and refuse to upgrade my science production or fight for science bonuses, what's going to happen? In both of these cases I think the answer is, those things will become a bottleneck for me getting things done, no matter what I try and do. So I guess that kind of means, you don't so much as need to try and find a solution to try and win, but you'll find yourself more or less forced into dealing with the issue until you can resolve it. And sometimes, the issue can cripple you. I've had a game IRL where I missed out on Iron in age I, which is fine, but then the two Coals were in the three last cards of age II. I found myself forced to take action cards repeatedly, simply because I couldn't afford to keep growing any other way, and it was repeatedly obvious what I needed was more resources.
Here's another idea: one solution for almost all of these things is "make more dudes and put them on it and/or upgrade your techs." Would you say it's true that if this was your solution to all of these things, that you won't be able to keep up? Would you say that you have to go out and find something else to help you with your life, whether that's military strength or a good wonder you really need, or some extra yellow dots?
To some degree I think a large part of the game is that you more or less need to upgrade everything, at least a little. But you can't keep everything in the most up-to-date form possible, that's generally impossible. It's not unusual for example to end the game on Irrigation as your only source of food (so that's an age I tech, providing for you in age IV). For example here's a recently finished game from BGO:
http://www.boardgaming-online.com/index.php?cnt=202&pl=7160648. You can see what I have there for each type of thing:
Food - Mechanised Agriculture (Age II). I didn't get an Age I food tech.
Resources - Coal (Age II) plus Iron (Age I), plus Transcontinental Railroad. I had really high resource production in this game (12 rocks through most of age III), which meant I also have a lot of expensive (resource wise) other things.
Science - Alchemy (Age I), and then Journalism (Age II), with Journalism not played until age III IIRC.
Happiness - Team Sports (Age II). Religion kept me going until then, and also Movies (age III) later on.
Military - This one I think you usually need probably a tech from most ages, to keep up. I have one from each age, giving a respectable 45 strength including other bonuses.
CAs - Constitutional Monarchy (Age II) was my government, with Code of Laws (Age I) providing an extra CA.
MAs - Again Constitutional Monarchy (Age II) providing 4 MAs. Military Theory (Age III) is a little misleading here since I played it last turn to power my Wonder up (it's an expansion wonder).
Well in a way this game is a little odd. I seem to have an unusual number of age II techs, but I think that's because I played a good number in age III. I also had a few other special techs like Cartography and Architecture. Hopefully what this demonstrates is that you can get by on a single upgrade to a lot of things - although two upgrades is often better.
