Also, I think there needs to be some thought on FTL method balance. Ships from other universes may have trouble navigating. Depending on the others. 

EVE FTL and mass effect are similar ish.. (jump gates essentially) but from Stellaris or Elite Dangerous who can jump light-years at a time without help. Not to mention 40k ftl by travelling though hell...

Personally I would simply bring everyone into one system and only change how effective each ship is. Some being slower or having a longer wait to enter ftl.