Walt I'm not personally bothered by having parts that aren't useful in multiplayer.
The FTL mechanic beeing not only a part but also a resource (fuel), i think you should care.
Multiplayer . . . . . and . . . . . Singleplayer . . . . . drifting . . . . . too . . . . . far . . . . . apart . . . . . does not feel right IMHO.
Especially thinking of Multiplayer-COOP here.
And shouldn't "fuel" be something that actually needs a container (tank, battery etc.)?
Credits beeing virtual is 100% comprehensible ofc but physical resources would need space?
(Yes i'm sooo looking forward to resource gathering/mining 😉 )
PS.: Discussing single elements of cosmooter has become very difficult because there are so much features projected for future that it is hard to imagine how the whole picture will finally look.