[AgentZero]

One thing I was thinking that would make ground combat a bit more interesting would be if Range and Rate-of-Fire actually mattered.
Here's one nince, simple way it could work.
Attacker:
Weapon 1: Range 3, ROF 1, Damage 10
Weapon 2: Range 2, ROF 1, Damage 50
Weapon 3: Range 1, ROF 1, Damage 60
Defender:
Weapon 1: Range 2: ROF 1, Damage 20
Weapon 2: Range 1: ROF 2, Damage 100

Combat starts at maximum range so in Turn 1, the Attacker takes no damage, being out of range, and inflicts 10 damage per unit on the defender. Round 2, the defender inflicts 20 damage per unit on the attacker, who in return deals out 60 damage (50+10). Round 3 and both sides inflict 120 damage on each other. Round 4 and the attacker does 120 again, but the defender only manages 20. And so forth.

Simple, but at least then range and ROF would be a consideration in troop/WP design.

On a vaguely related matter, I'd like to see a fighter component like 'Atmospheric Stabilizers' that give fighters the ability to conduct precision attacks against planets. When you give an attack order to properly equipped fighters, you'd be given the option of:
Attack Population Centres (kill people)
Attack Facilities
Attack Troops
Attack Fortifications (Weapons Platforms)

This would add a strategic dimension to fighter use, since they would be perfect for softening up a planet before invasion, while orbital bombardment from ships would just cause widespread destruction, and end mostly end up damaging the things you want to capture intact.