Thanks yariplus. I really appreciate this kind of feedback.
Yeah, cards should definitely behave like an actual deck. I had it in mind from the start. Current "blind" rng is just a proxy for that. Too bad there wasn't enough time to implement and test it. I don't have much experience with deck building games so I didn't want to improvise. Any suggestions regarding card mechanics are welcome.
I also thought about some sort of bonuses/modifiers. Most obvious one being an extra card draw per X cities obliterated in a turn. This would give player more power to recover from crowded situations and probably eliminate the current (nasty) point of no return at about 35%. It may make game more engaging as it feels good to turn around nigh impossible situations. I'll actually test this asap.
Deck modifiers you mentioned also sound good. I'll think about it and test some of the possibilities.
I had an idea similar to yours that disasters could cause bonus damage depending on where you place them, but couldn't really think of ways to do it for every type of disaster without introducing more terrain diversity. This was too much for the jam version as it adds a layer of complexity that'd probably be hard to balance without extensive testing. However if draws are coming from a configured deck then there is no need for symmetry of power between various types of disasters. If, for example, flood is the only type that gets a terrain bonus, its power can be balanced out by having fewer of them in a deck. This all sounds good and is surely worth exploring.
I kept the order of disaster placement rigid because it forces you to think and combine in advance. Which is accordant with the jam theme. But also simplifies interaction.
Mid-turn city shrinkage ended up a plausible gameplay element which, again, forces you to account for it in advance. On the other hand, the rules regarding this could be made strict so that city radius doesn't shrink in-between disasters. Could work both ways.
Similar to this, there's one other thing whose importance may not be obvious - oscillating disaster radius. This is the only "real-time" element in the game. Which may be weird but I think it works. Some modifiers could perhaps be introduced here too, e.g. bigger radius amplitude at the cost of faster speed...