Though there is nothing wrong as is
Here are just a bunch of ideas I had last night that would make the EV games better (even though there is nothing wrong with them as they are now).
Most of the ideas couldn't be implemented via a TC plug, so they would be perfect for EV4 (even though it has been stated there never will be an EV4).
Planetary Domination
1. Ground Defenses that require being disabled (can only be done with disabling weaponry) or destroyed before being able to dominate a planet.
2. Most weaponry able to affect both ships and planetary Ground Defenses (certain weapons wouldn't last long enough through the atmosphere).
3. Drop Ships designed to drop ground troops on a planet to aid in destroying / disabling Ground Defenses (wether a defense is destroyed or disabled is random).
4. Ammo based Ground Defenses capable of running out, although Ground Defenses like Laser Batteries and Ion Cannons would be unlimited ammo.
5. Planet gains point defense systems to ward off Missile Based Planet Killing Weapons, Bombers, Drop Ships and regular missiles / torpedoes.
6. Once a planet has been captured you'll need to buy new Ground Defenses of those you destroyed. Those defenses you disabled become yours.
7. If the system has a nearby neighbor of the same Government, then they will send ships and troops to recapture your dominated planet after a few months. The more / better defenses you build, the longer it'll take the enemy capture fleet to recapture the planet once they arrive. You can also come back and destroy the enemy fleet resetting the recapture system (meaning they'll come back after the same amount of months as before). If there are no neighbors of the same Government as the system your dominated planet/s is in, then no-one will come to reclaim it (unless the storyline you are playing causes them to take over a neighboring system).
8. If the planet has an orbiting space station/s, it / they will need to be captured / destroyed before you can deploy ground troops and capture the planet below.
9. Planetary upgrade centre becomes availible on captured planet / space station after you have captured it. In there you can purchase things like point defense systems, planetary ground defenses and general upgrades (like planetary docking rings for planets or general size upgrade for space stations, making it's graphic bigger and also allowing you to buy more weapon systems for it).
Planet Killing
1. Bio-weapons - The most expensive type of planet killing weapon, when used they kill everything on the world, after a number of days the effect wears off and you can re-colonize the planet using Colony Ships.
2. Nuclear Missiles - The planet becomes completely unlivable and the effects take years to wear off.
3. Tectonic Warheads - The planet gets annihilated to the point that it becomes a airless rock, only the size of a small moon.
4. Planet Killer Beam Weaponry - The planet gets annihilated, leaving only asteroids in it's wake (system gains an asteroids).
Landing and Docking
1. Large ships would not be able to land on a planet (they also can't be built on them, so they won't be in the ship yards or gain upgrades from them). Instead large ships would only be available from and upgradable from space docks or planetary docking rings like the Kane Band.
2. Shuttle Bays can be purchased for large ships in order to allow you to land on a planet, or you can use a fighter / bomber / teleporter system. In the case of Shuttles, Bombers and Fighters your main ship launches the ship and joins your escort fleet, you then can land on the planet. Afterwards you can re-enter your ship or one of your escorts by selecting them in the targeting computer and boarding them.
3. Certain large ships like Destroyers and Leviathans can get an upgrade that allows them to land on planets (ie the dropship upgrade), it also allows you and your escorts (with this upgrade) to carry and deploy ground troops to dominate planets.
4. Once you've dominated a planet you can spend allot of money build a planetary docking ring which allows your large ships without the dropship upgrade to dock with the planet. Planetary Docking rings also make it easier for both you and recapture fleets to deploy ground troops.
5. Teleporter systems allow you to deploy ground troops and land on planets without the need for Shuttles or the dropship upgrade.
Boarding
1. You can change your ship simply by targeting one of your captured escorts, moving close and inline with them and pressing the B key, this also allows you custom upgrade each escort. Any changes you make will be saved even if you change ship. You cannot swap onto a hired ship, they require upgrading the normal way (ie like Nova handles Escort upgrading atm).
2. Boarding Torpedoes and assault shuttles make it allot easier to capture enemy ships through docking. You send your assault shuttles using the boarding action key whilst an enemies shields are down and is targeted from afar (you need to have an assault shuttle bay first). Or you can use Boarding torpedoes which will only fire if the enemy ship's shields are down. Either way boarding torpedoes and Assault shuttles decrease the enemies crew count increases your capture chance when you board them in the regular way. Both types of boarding increasers also cause damage to the ship (while the troops are onboard the enemy ship, they'll attempt to disable it whilst they kill the enemy crew, this also slows the enemy reload time and the turning of the enemy ship).
Boarding Torpedoes and Assault Shuttles also require that you have purchased Boarding Troops to send over on them.
Personnel
1. Recruitment centre added to planets and space stations, that allows you to purchase crew, veteran officers, boarding troops, ground troops, colonizers and terra-former experts.
2. When you purchase a ship in the ship yards, you only get a skeleton crew (the bare minimum people needed to get the ship running) so your ship is very slow and weapons reload slowly. If you purchase crew from the Recruitment centre your ship moves more up to the max effectiveness, all ships have their own crew limits (and so max normal reload and turning speeds, only upgrades can increase those speeds afterwards).
3. Veteran Officers have different types for different purposes like in Arpia, mostly the increase the effectiveness of things like your sensors, jammers etc.
4. Colonizers are used to populate habitable planets / space stations which are abandoned (wether through bio-weapons or otherwise).
5. Ground troops are used to disable / destroy planetary ground defenses, normally you'll lose a great many when invading a planet or station with a higher military rating than your troops (you lose less per difference). If you successfully dominate a planet, you lose all your ground troops (they stay on the planet to man the defenses and impose your rule).
6. Terra-former experts can be deployed on an inhabitable planet, to terra-form it (they speed up the recovery process when used on planets affected by bio-weapons and nuclear missiles, and make it possible for all but the most inhospitable planets to be colonized (only planets you can't land on can't be terra-formed).
Systems
1. All solar systems gain a star / super nova / pulsar / black hole in it's centre.
2. All systems get made a ton bigger.
3. All systems get all their planets (ie the Sol system gets all ten planets and all it's moons, all in correct placement in reference to the Sun) - Note the Tenth planet is the recently discovered planet Xenia located earlier this year (2005).
4. Gravity is made more intelligent, meaning black holes will suck you in, and planets will gently pull you towards them. The bigger the mass the more pull it has, and the more powerful engines you need. Inertia-less ships are unaffected. Certain planets like Jupiter will kill you if you are pulled into them. Stars / pulsars / super novas / black holes will also kill you.
Ship classifications
1. Bombers (best suited to attack medium - large ships), large warships (ie like Carriers, or Ravens) , dropships and assault shuttles added to the escort types.
2. Ships able to be order to only attack certain types (ie fighters can be ordered to attack bombers only, or other fighters). Ie the same as listed escorts. Except an extra option is added for fighters to attack missiles, boarding torpedoes etc.