Last week I played a Axis & Allies Naval Miniatures game which is similar in some aspects to Starmada (at least you have single ships and fighter squadrons). It was simple, fun and easy to play. We could learn the rules in 20-30 minutes and we used all of them and not just the basic rules. One game lasted 1,5h and we played 3 of them in a row. This I call a good gaming evening. I doubt that I would have enjoyed the evening as much if the game had more complex rules.
It really sounds like you're looking for a different type of game than Starmada, rather than a simpler version of the existing game -- which, as others have pointed out, is exactly what the "essential" Starmada rules provide.
For what it's worth, I've long wondered what would happen if I went back to an earlier (simpler?) version of Starmada (version 2, perhaps) and redeveloped it along the lines of a game like A&A Naval or the tactical combat system in the Avalanche Press games... maybe one day I'll actually do that.