[Makhil]

The major flaw i see is with the travel system. By making it harder to attack far away planets you restrict the number of targets. In a sector already occupied by alliance mates, there will be few targets available, and people will end up hitting always the same bunch.
I find it a real problem in a 1k player universe, with an average of 250 planets per quadrant and potentialy a 100 member base alliance dominating a quadrant ( i wouldn't like to end up in that one)

Travel research should be used to allow far way travel at the same eta as closer ones. Example: travel1 for quadrant1 eta bonus, Travel2 for quadrant2, etc...

An eta5 should be kept to the 8 adjacent planets.

In that new system, I think each player should not control a planet but a solar system. At first it would just be a change of name, but later it can open up more features (exploration branch in the tech tree to visit other planets and get bonuses from their exploitation).