I would be nice if more options and realism, was added to the weapons.

1: One possibility would be to add a range limit to each weapon. This would allow ships to do battle with ships in other sectors instead of being right beside them. The further away you are from your opponent, the less damage a laser could do for example. Missiles would run out of power at a certain distance and loose accuracy the further they go. Mass weapons would loose speed and energy. Now there could actually be a bigger difference between laser 1 and 5 if range increase is added to the mix.

2: Ships should also be able to fire their weapons at planets to destroy improvements, and kill solders to support ground troops.

3: Military base stations should be able to attack enemy ships that pass within "X" distance from them instead of just being sitting ducks as they presently are. In fact, they are so easy to destroy that I don't waste time creating them anymore. They need more offensive power so they can stand up to a fleet of attackers. Right now it is not "if" but "when" they will be destroyed. When they are under attack, they should be able to ask for assistance from any surrounding ship.

4: Planets should have their own ground base laser and missile defence systems to shoot down attacking ships. They should have a range of one to 5 sectors. This could also serve as a defence against influence station that are poisoning your people. I think that this would increase the difficulty of interplanetary war and require a greater amount of strategic planing for invasions since your opponent could now wipe out your fleet with ground based weapons even if they have no ships in orbit. Intelligence and espionage would play a key part in assessing the enemies "ground to space" defensive capabilities. Maybe radar ships would be needed for ground survey operations.