The main obstacle I keep anticipating is that I can’t really get “outside of my own head” for having the adventure/story develop and progress in creative ways. I don’t want to be writing a fantasy book (meaning, I don’t want to be planning ahead what happens), I want myself to be surprised by the story, but I still want the adventure to be more open and freeform than, say, a Fighting Fantasy or Lone Wolf gamebook. Of course, short of developing a split personality, that’s not easily achievable 
As for the potential sci-fi version, I’m very fascinated by Traveller as I’ve never really experienced it in any way, so by all means do emulate the style of that (assuming you’re inclined to, anyway).