A remake would need a bigger budget. More money to afford better visual effects, more money to afford a live orchestral score, and more money to afford everything from longer shooting hours, better guest actors, less clunky set design, etc.
I could pick apart story turns I didn't like, unfortunate cast departures, etc., but that's a different can of worms. Babylon 5 was great for what it was-- a science fiction epic made on a shoe-string budget. If you're going to make it again, do it with the money the concept deserves, or just leave it be, because the way the series used every single penny is unlikely to be repeated.