For the separate mode: would building ships be the only difference? I think there needs to be enough differences between the other modes to warrant a completely separate mode
(for the inventory hardcap, sure, I'll put it in one day lol)
I haven't worded it as well as I should have - sorry about that.
How about making it a prompt, just like the one asking you whether you'd like to play with/without the tutorial at the start of a new game?
Yeah, that could be a possibility, I'll think about that