So I'll rant. The starting point for a big, online, Star Trek game, would be a VERY large universe to play in. Thousands of stars, with most of it unknown space, filled with unknown aliens, lifeforms, gaseous anomalies, planets to scan and/or investigate. A game that conveys a vastness to space similar to how Starflight did back in 1987. Let it be large enough, that you can have both gatherings of large numbers of players, and still be able to get isolated. Big, and full of interesting stuff. Strange lifeforms that attack your landing party. Ancient ruins, artifacts.
Starflight had its grind, also - large amounts of mining ought to be an optional activity - but that game captured the feeling of exploring space and encountering aliens better than any I know of since.