So barring someone buying up the IP the rules pretty much have to go to community based if they are to evolve. And even if someone does buy up the IP, a community set of rules would give them a very good starting point for any revamp of the "new official" rules.
I would like to start with what direction we want the gameplay to go. What do we want the game to play like? Not things like specific rule changes like "I want to see the % large in list building change by 5%" or "ships X, Y, and Z in 'this' ORBAT need more defense/firepower/etc." What are the goals of the rule changes, rather than what specifically are the rules. Something like "a stronger focus on ship size diversity" or "more reasons or ability to take mixed theater forces" would be good though.
Personally I would like to see games last more rounds, not necessarily longer games but games that go 4+ rounds instead of ones that end in 2.
More advantage to out maneuvering or out flanks someone, which would in turn make smaller ships more valuable.
Simpler mechanics for fixed channel weapons.
Make rocket and torpedo attacks more thematic and function differently than "guns that can be countered with AA/CC."
More variety in scenario and win conditions, especially so no "one list" can be the best option for every scenario that might come up.
More focus on "balanced lists" so focusing on any one single type of thing is rarely going to be better than a more balanced, inclusive list.
More, too, but that seems like a good place to start for the OP.