To answer more to the point, I'd have to preface and say that I'm not a Homecoming player and might never be. CoH was my favourite game, but I'm not much of a gamer these days. I'm still fond of CoH, of course, and might at some point try it, and the air of legitimacy that an official server would provide could certainly help in that.
Still, I'm unlikely to play if the game is made subscription based, or has an entry cost of more than $10. Though I might donate such a sum anyway, just for old times sake, like the Kickstarter backing I sometimes do even though I know I won't play the games.
If an official server means charging people for stuff, that's cool. I've never been against buying cosmetic items, or even game systems (paying for classes, housing, whatever). I've done it in EverQuest II and wouldn't mind doing it in another game.
But please don't go the CoH Freedom way. That was an incredibly convoluted system that really made non-sub players feel like second tier citizens.
Regarding game changes, the things I liked about CoH were on one hand its solo friendliness, casual friendliness and simplicity. Really, it was just something that one could enter, play for half an hour and still feel a sense of accomplishment. One could study things in more details and get more efficient, but it was also noob and casual friendly. And it was also quite easy to find a group if I wanted that, and then apologise and drop it if I needed to go.
The other thing was the fact that it had stories, and a lot of options for character concepts and costumes, and it actually encouraged people to write some text about their characters. It also had scripts for advanced users, which allowed even more outrageous character concepts to be created (like a balloon clown I created at some point, who'd jump all the time and randomly spew jokes). And the fact that it wasn't a hard game meant that I could select powers which weren't optimal for gameplay but fit a character concept. Oh, and having tons of character slots.
Different people would have different things they like about CoH, but these are the things I personally would like to see kept.