I'm all in favour of keeping the end sequence of ESB pretty much as it is.
This scene is IMO about as close to a Binary Sunset moment that ESB gets, and the galaxy shot has become fairly iconic of the mood. Change the visual too much, and the original mood is lost. As for astronomic accuracy, we must remember Star Wars is Science Fantasy, not Science Fiction. We don't need Star Trek style explanations for every technology and phenomenon, and that IMO is one of the great differences between the two universes. Whether we're looking at a star formation, the local galaxy viewed from the outer edge (rim?), bright matter circling an occluded black hole or a nearby galaxy viewed through some lensing effect of interstellar dust it doesn't really matter. Though I'll freely admit I am rather fond of the Rishi Maze explanation (I feel it ties in with AOTC rather well on a subtle level, and is still plenty big for a fleet to 'hide' in).
If we do start down the dark path of fixing things that are implausible to current science, then even the Binary Sunset shot, where two nearby stars appear the same size and in close proximity from an orbiting planet, is in trouble.
And as for the Nebulon B medical ship, well ditto for the whole plausibility thing, and I guess to a lesser extent it's a bit of an icon in its own right. Plus it looks kind of like a toy pistol, in a good way. Fine if the point where it docks to the Falcon needs fixing, but that's just continuity.
I have a feeling in the Revisited Battle of Endor the vulnerability of that narrow bridge may become apparent :)