My guess is that he’d just as soon make his own  straight sci-fi, but Fox will only underwrite the show if jokes are part of the pitch.

Pretty much this. It’s definitely not a parody.

Here’s the thing: I don’t think MacFarlane intended it to be a parody. I think he meant for it to be a loving homage to Star Trek: The Next Generation, albeit with dick jokes. Compared to something like Galaxy Quest or Other Space, it’s pretty much a straight pastiche of TNG with a lot of Family Guy-style humor…

I’m guessing he gains the weight from not exercising (robot legs don’t burn calories).