7 villages! That's a lot for an expansion with about 30 cards. Then again I feel like I've played a lot of village-less games lately, so maybe increasing the average number of villages in the pool is a good thing.
Arcade: This is way weaker than Plaza for a few reasons. When you discard a Copper with Plaza, you're basically saving the $1 the Copper would have gotten you for a future turn. But Arcade doesn't save the effect of the action you discard, and +1 Villager is usually pretty poor compensation since your Actions are generally far stronger than a Copper. Add to that the fact that Arcade gives you +2 Actions, so you'd almost always rather play the Action cards instead of discarding them. I think this card needs major changes, probably away from being a village.
Cahoots: A little too complex, I think. Also I'm trying to figure out if this really provides any gameplay that Ironmonger doesn't already. It's a Laboratory far more often, I'm guessing. But I think overall it's too similar. Perhaps you can rework the concept of "if your top card matches the one of the player to your left" into a simpler, more unique form.
Cottages: Well, this seems reasonable, but maybe not exciting. Even once it activates, it's just a village. I think it needs a little something extra. Nothing crazy, since you usually want to trash your Coppers anyway, but something.
Horse Ranch: Hmm, interesting. I like this one. As you say it's a village overall, but most of the benefit is deferred. I would cost it at $3! It's not strictly better than Village, so I think you can get away with that.
Mining Town: In general, effects shouldn't just happen at any time during your turn. Being able to do things in the middle of resolving effects is asking for trouble. Beyond that, I'd say this seems strong. The way it's worded, you can gain a Gold per time you've played a Mining Town, and Mining Towns are cheap. Also Natural Resource should be white and green since it's an Action-Victory card. Natural Resource will certainly shake up openings, which is mostly good, though at this point lots of cards do that already.
Sojourn: This is totally reasonable. A little dull, but a totally fine village and well-costed.
Township: This seems promising. I bet reasonably often you'll be able to get the benefit, but sometimes you won't. I'm guessing it's quite strong and maybe too strong, but I'm not willing to make that claim before testing it out.