Do we have any evidence that Roddenberry did, in fact, try to sell them on this idea of the ship being a star?
I haven't seen anything indicating this. If he did, it obviously didn't work. NBC wanted to see strange new worlds as often as possible, and grumbled at nearly every bottle show outline submitted to them.
I know Warped9
has made it there, but has anyone else made it to the chapter on 'The Alternative Factor?' I still think the author's central narrative there -- that NBC forced a late re-write to avoid an interracial (that is, black/white) romance -- is asserted without any evidence. There's no memo that actually says it, and no interview after the fact that supports it.
Thinking further, if this is true, it's sort of odd that Roddenberry (who loved to blame NBC) never opened up about this in public. He never had a problem asserting the network was racist or too meddling before.