I fixed the crashing problem. Now I am using DarthMod and a bunch of other minor mods and they're all working. Also I'm working on changing the faction colors of the Prussian Republic so everything changes from Prussian blue to black when Prussia becomes a republic (Yay, custom units with extensive retexturing not needed!) :D

After I get the faction color thing worked out I'm gonna start a new campaign as Prussia and create a Prussian-German Republic with a unified Germany.