More differen combat will be good, but the victory/zones system doesn't make any sense for almost all combats, particularly two fleets just meeting in space. Sure, you can add the rules and justify it with a hand wave, but it ought to be a last resort, because hand waves are for mediocre star trek episodes; making sense is better.
Here are a few random ideas:
-Buff giving ships as objectives. Instead of objectives or zones try to force combat into a certain shape, there should be ships with ECM/etc hullmods that provide buffs as good as objectives, but in a large area of effect zone (so people/AI won't hide them at the edge of the map). Yea, this takes away capturing, but capturing isn't that great. It does make defense more important. Perhaps the AI would have to be updated to really catch bullets for friendly ships marked with defense order. The current ECM mechanics aren't common or powerful enough to make those ships with ecm hullmods into defacto objectives.
Putting destroy-able, buff providing infrastructure on stations is also good. Combat with stations already is "zone of control combat" because in order to win the combat, you have to control the vulnerable areas around the station in order to a) defend it or b) destroy it. This is an example of a good way to do combat. You don't need arbitrary zones or victory points for stations/big things.
Round map Yea this won't solve a lot of issues, but at least there won't be corners.
rebalance all combat to be much more faster/destructive so there would be less slow chases along the map edge? e.g. instead of having 15 missiles that go really slowly across the map and do almost no damage individually, have 1 missile that goes really fast and does lots of damage? More Iaian M Banks and less pre WWI fleet combat.
Combat in the middle The map could be bigger, but both fleets should spawn closer to the middle, then have all edges be retreatable. But if the map is bigger, there could be more boring long chases.
classic no deployment choice option. Really, the map should be much bigger, and both fleets should spawn in their entirety with no option to hold ships back. This would create battle lines to protect freighters, etc, but probably the game performance can't handle it because of java being slow or whatever technical reason I don't know about.
Having all the edges be auto retreat zones in any case is probably good. Yea, it gets a bit awkward to decide what to do with all the ships that retreated/escaped, but maybe it's ok for the two fleets after combat to reappraise their respective numbers and decide whether to attack again or try to flee. But This might result in boring chain combats of you lose, you lose, you lose, you finally die.
Unless...
Have the campaign map keep iterating during combat so retreating ships form separate fleets obviously it would iterate really slow. So that you could have ships retreat from combat and they'd form additional baby fleets that would fly away or do whatever and then you could regroup with them afterwards or summon them back to you with a sensor ping.
some kind of routing mechanic Like in dominions 5, where whenever a ship retreats by going to the edge of the map, it 'routes' and is automatically moved a certain distance away on the campaign map (based on burn speed). This is like the above somewhat.
Let's think up more ideas.