I could always invrease the limit.
@ Acken: I would humbly suggest this. Right now it seems CS never have more than 2-3 units, and they fall like dominoes. There's got to be another solution. For starters, we could possibly up the movement speed of merchants, making it easier to move around any blocking units.
@YCJ Yes it was me who said that about Aesthetics. I know it was an exaggeration. It's very difficult to compete with an Aesthetics civ if you don't take it yourself, and you're likely to suffer a happiness penalty as a result, if you adopt a different Ideology. On reflection, though, this might be reasonable, as it gives the culture focused civ an advantage over a science focused civ, and without that advantage I would estimate the science focused civ would be the clear winner. Having to devote more resources to happiness might actually end up being balanced.
I agree that Exploration as it stands is rarely useful. I'm also finding the commerce tree rather weak. Trading post spam has been removed from the game, and the purchase discounts have been nerfed, so commerce doesn't give as much gold.
Acken I saw in your coding that you were toying with the idea of having commerce make all your specialists produce an extra gold. I toyed with that myself by editing your mod to allow for it. The extra gold ended up being similar to what trading post spam used to produce.
I just find commerce a difficult tree to adopt. If I'm going wide I usually manage to grab a religion, and if I do so it's always useful to take Piety, and when I've done that I don't have the culture left over to go into commerce because I need it for my ideology and rationalism. If I'm going for a CV I take Aesthetics, obviously.
I think the only time commerce works is when you take it as your second tree, but I often find that the other choices, such as Piety, Patronage, or Aesthetics, are better. After the second tree, Rationalism is better.
Commerce has some good bonuses towards the end, such as the extra trade route and extra happiness from luxuries, but its earlier policies are rather weak, imo. I'd be more likely to adopt commerce if it gave more serious bonuses early on. Perhaps the extra happiness from luxuries bonus could come earlier in the tree? Also, I think bonuses to trade routes shouldn't be split between exploration and commerce, and should instead be all fit into commerce. Exploration can get something else.
What would be amazing is if somehow the science received from trade routes could be boosted by a commerce policy. I'm not sure how that could be coded, though.
Anyway, maybe I'm the outlier here. Do other people like and use commerce often? Am I the exception?