Overall I have to say I am having far more fun than I thought I would be having; I started an un-modded game of the USCA and right now in 1885 I am #2 in the world. I've focused primarily on education and industrialization, but along the way picked up quite a bit of prestige too. There are a few things I'm noticing that could be fixed though.
A lot of techs feel underpowered at a glance or out of place. Culture -> Psychology only having military benefits until Behaviorism, for example. Other techs feel very weak, such as the Commerce branch; most of these I felt I didn't need, as the benefits seem not worth the investment, though I did improve my tax efficiency in order to offset the newly heightened cost of running a navy.
Uncolonized provinces seem to misreport their total population from time to time. Looks like a restart of the client works to fix it. Here I was really hoping for several million new citizens in each African state! Speaking of colonization, does anyone else think that assimilation works far too fast in colonial holdings? I was thinking maybe there could be little to no assimilation until the territory gains some immigration and bureaucrats, then there would be partial assimilation until you gained cores on that territory. Occupied territory would also face lowered assimilation, much like a newly minted state, until you gained cores.
Would it hurt many nations if they couldn't build factories unless they had a land connection to their capital? This might work to solve the British Menace building hundreds of factories in India.
Edit: I'd love National Focuses to be tweaked too. Maybe every 500k instead of 1M and add a few new ones, like Encourage Immigration or Encourage Assimilation.