Weird is good. Let's go with weird. You evidently have knack for weird.
That crafting system probably gets out of hand when people start coming up with new multifunctional parts. And more parts there are, harder it is to predict overpowered combinations. Perhaps limit availability of most potential parts? Maybe have a mission to scavange those parts from dangerous places?
You could probably leave the "on ship" part entirely for players, or co-GMs, but that's a big question of trust. It is easier to trust actual GM than your fellow players.
As per handling fights in forum games general I have been trying to come up with ideas to solve any fight in max three turns. Not much of luck yet with good ideas. This is what I have thought so far: Player comes across hostile entity. GM tells some details about the enemy and asks player how s/he wants to handle this situation. Basically "Here's enemy, it looks like this, it probably has these weapons, here's possible covers. You got this stuff. How you wanna handle it? Agressively spraying bullets everywhere, berserking up to his face, defensively taking potshots from cover, running on walls, or what?" Then roll and write prose how the fight goes and when it starts look bad for player, stop and ask if he's gonna change tactics or run away. And by third turn someone is either dead, incapacited or running away.
It leaves a lot less for players to roleplay, but solves fights reasonably fast. And gives opportunity to write more detailed turns for once (not hinting anything here). Dunno how it works in open world where more forces can join the battle at any time, but probably works on 1vs1. Probably. Should test it and think some more.