On winecfg you can try the checks on the Graphics tab, it shouldn’t break anything. Also, try to change the Windows version. Sometimes either XP or 7 work better. You’re right about it being c++, not sure which one I installed, maybe this one: https://github.com/abbodi1406/vcredist
It seems with Heliboard you have to switch between languages rather than having it detected automatically. It also doesn’t support swiping so not really a replacement for Swiftkey yet, for me at least.