I agree with your opinion. Competition in a game is a big aspect personally for me and I'm anxious to see how this game will flourish.
Of course, the basics have to be covered first, such as,
- Servers: Having played SF1 before AVA and being involved in the latter since its release, a big part of the game is the infrastructure its ran on. The better the quality, the better the game experience through less disconnects and better hit registry. The client is no problem, I personally get surprisingly good registry on both the korean and chinese servers.
- GM involvement/Community: A actively engaged administration and community will heavily benefit the game.
- Anti Cheat: A no brainer, got to maintain a much as possible cheat free environment.
- Weapon balance: Evidently a problem in most free2plays, once a large list of weapons is available, you usually just get 2-3 weapons that everyone uses. I'm happy to notice that in the other versions of SF2, a wide variety of guns are used by players.
Pretty much it imo.