The terrain still kind of sucks in many areas. There are way too many plains in Russia. Provs 1597(Bryansk: the very name of the same means "in the middle of the deep wood"), 179(Murom), 168(Arzamas), 167(Ivanovo), 177(Yaroslavl),178(Vladimir), 176(Zagorsk), 1536(Syktyvkar), 174(Kalinin), 289(Torzhok), 191(Staraia Russa), 185(Tihvin), 172(Vytegra) and 153(Kirillov) should all be Forests since they are in an area extensively covered with deep woods that are treated as open space ingame. Tambov(156) could be forest too: it was the forests of this region that concealed the rebellous hordes of Antonov-Ovseenko in 1921. Kirishi(287) should be either wood or marsh, certainly not plains. Tiumen(1593) should be forest.
Also Joensuu(149) and Kajaani(136) in Finland could be made woods as well - that's quite logical.
On the other hand I'd recommend making Tchernigov (241) plains due to its strategic location. It was certainly possible to encircle Kiev without getting in those marshes. I hardly see the point of Herson(251) and Melitopol(250) being marshes either. Let Djankoi be marshes to represent Perekop and Sivash and that would be enough. You could add a "maritime" crossing frop Melitopol to Djankoi too(I don't know if its possible to add a province connection), the Reds did it in 1920, the strait crossing malus being adequate to represent a crossing of a 1 meter deep, but large body of water.
Sukhumi(1845) should be at least hills or even moutains.
And about infrastructure I think it simply should be at least halved, maybe even more, to represent the actual terrain in the SU. 50 in Guriev is like a joke.