So, a couple of notes on the format. First of all, 4-player, boo. Okay, so it's good that it's not just one-and-done, but two games isn't a lot better, and in general, I don't like facing the same opponents over again OR having to not only win your group, but win it by enough, though I can see logistical reasons for that.
VP tiebreaks == very very bad. Leads to running up score, is hugely dependent on how good the other people at your table are, generally promotes you going for things other than 'I can end the game with a win right now, so I will', etc. etc. this has been talked about to death.
The point system is pretty stupid though. I mean, I like point systems. But this one is dumb. It rewards getting last. Yup, I said it, and I am surprised nobody else has pointed it out yet, but this system rewards last place. I mean, look at the most basic point system you can think of: something like a 3/2/1/0 or a 4/3/2/1 (whatever, they're functionally equivalent to each other, because the difference in scores from one place to the next is consistent). This system says that 1st and 3rd is no better or worse than 2nd and 2nd, etc. etc. Okay, fine. Now I personally think that you should make a system that further rewards winning, beyond this, because winning really is the name of the game, and one which penalizes last place, too. Well, I mean, you can never do better than 1st, and you can never do worse than last, so there's a bottomless pit, and an unscalable mountain there, irrespectively, and you should take account of that. Ok, fine though, just having even doesn't seem all that unreasonable to me.
But this point system, the one that got used, actually benefits last place! The drop between 1st-2nd is the same as the drop from 2nd to 3rd, but from 3rd to 4th is less. Accordingly, any group of finishes which would be equal under the vanilla system, if one includes a last, and the other doesn't, the one which has last does better here. For example, 1st and last against 2nd and 3rd. 1+4 wins here. Well, ok, that doesn't seem terrible, because winning is good. But how about this - 2nd and 4th beats 3rd and 3rd. Huh? Really? Okay whatever, I'm making too big a deal out of it, and it probably won't matter in the given format, but.... I just thought that it was very strange.
As for the sets:
Semi 1: The only engine here that I can see is city+rabble, and man that seems way too slow. Unless you are fortunate enough to spike a forge on your first reshuffle, I guess. But if you don't play that engine, what do you do? I think monument is probably better than bishop, early on at least, because of the effect of your opponents trashing. So I probably go monument+RS+big money, but watch out for what your opponents do, and pick up bishops over extra monuments later on perhaps. I guess the other thing is, you might be able to actually build the engine if all of your opponents go bishop, because that is a lot of trashing help. And the more opponents go bishop, the better your own bishop is, because the less your extra trashing helps them. I'm also not totally sure about the dynamics of city in 4-player, but I would guess you don't want to be the first or second person to go for them.
Semi game 2: So here, with 4p, it is interesting. You will probably be so flooded with junk, I am not sure that KC is worth it. You definitely want to get lots of mountebank, and then because copper and curse will run out fast, dive for green, even smaller green. Platinum should basically never be bought here, prolly not venture really, either. I expect you would end up with lots o' duchies.
Finals game 1: This set is a bit of a power vacuum, nothing terribly strong. Well, ambassador is interesting, but there's no real engine here, and you can't win an ambassador war in 4p anyway. On the other hand, if just one person goes ambassador, then he actually can, so there is this weird dynamic there. But anyway, I don't think this is a board to try to test those waters, with no engine. So then, do you want moneylender, or island, or bureaucrat, or what? I think An island, and then maybe moneylender. Pick up lab on 5, but always prefer gold. And basically play a pretty boring big money game.
Finals game 2: I'm interested to hear that you think this set is interesting, because it looks really boring to me! Just play wharf+fishing village, and if your opponent is looking at possession, like a real possibility soon, green a little early. They can't really afford to not play your durations for you so so much, because the possession turn is more of an asset for them than an attack on you, particularly in a 4p game. Possession should also be pretty slow against something like this, particularly in 4p. I mean, maybe they possess you once, I doubt twice, and that just does not seem worth it. And golem and alchemist certainly aren't enough support for me to go potion here - vineyard might be, if I wouldn't expect the game to be so short (like if it were 2 player).