My concern with this idea of "space wizards" being the principle that actually powers FTL travel, artificial gravity, and other technologies for which there is no real technological equivalent—but which space opera readers (and viewers, and gamers, etc.) kind of expect—is that they end up looking like D&D wizards, except that I have to make up a whole bunch of space-related spells for them. That not only sounds like a lot of work, but it also sounds like something that I doubt I'm really very interested in doing, because the end result will likely be unsatisfactory.
One solution that is growing on me, and which I'm seriously considering, is to make them essentially nothing more than a plot element; i.e., there won't be mechanics to explain exactly how they work, and they won't be playable characters. In this, I'm partially influenced, I believe, by the old show Thundarr the Barbarian, where (with a single exception; Thundarr's side-kick Ariel) sorcerers were inhuman, strange, monstrosities, for the most part. Mindok the wizard, to use one example, is a classic brain in a jar looking to reanimate prehistoric astronauts so that they can build him a new body (not sure why he thought they could do that.) Stryia has mutated an army of shark people to threaten humanity, Morag is essentially a psychic vampire, etc. These are all really bizarre things that, as I said, serve more as plot devices than as anything like a player character.
I admit that part of the reason I like this is because it requires less work for me to develop anything for the m20 iteration of the setting, which would be nice, because I really have no idea in what direction to develop that anyway. I'll noodle around the concept a bit more before I decide for sure.
As for fiction writing in the setting—well, I hardly need to develop m20 mechanics to do that anyway, right?