Evasion:
Nice idea, it would most likely bring more depth into combat - or complicate it unnecessarily, hard to decide on this one.

Ground forces:
100% agreed, I'd love to see real ground forces. I also would like to see that you can "capture" enemy population and assimilate them into your culture (or enslave them if you're evil). It would be even funnier if the game would notice the different population and show them somewhere - like I have 12 billion Drengi and 4 billion Torian slaves in my empire... but right now, my righteous Altarian goody two shoes, who are considered to be "good" in my current game, love nothing more to kill every last man, women and child on a planet they have to invade to force a peace treaty. Now that's not really something a "good" race should do, eh? Dedicated ground forces and a separated civilian populace would be a great addition to the game, at least in my opinion. In my perfect dream world you could even design ground forces like you design ships...

Elite units:
Nice idea, would be fun to have a squad of Elite ships / soldiers, but we already have that in a small way with ship levels and hit points I guess.

Heh... stopwatch.

Just my opinion, but I'm not sure cloaking devices would add anything to the game. It would be overpowering without a matching counter-tech of some kind; a decloaking field or special sensor tech. Once you see the enemy has researched the tech, or has built ships with cloaking devices, you'd automatically research and deploy the de-cloaking tech. And the AI should do the same. So you're back to square one, with both sides evenly matched and countered.

If the game design was better at hiding what the enemy is researching, and what upgrades are on their ships, then there might be some temporary advantage to a cloaking device until the other side catches up. But right now the game exposes everything the other side is doing, so I think this isn't very useful.

Reducing sensor range instead of full invisibility is an interesting idea. More of a sensor jammer than a full cloak.... you could sneak a parsec or two closer to an objective without being detected. So it's a strategic advantage instead of a tactical/combat advantage, like putting engines, sensors, or life support on a warship. You'd have to think about whether that's more important than one more weapon or a defense module, so it's somewhat self-balancing.

The player's cloaked ship would have to remain visible at all times on the map, so it could be managed and steered. An AI ship or fleet in cloaked mode would pop in and out of view as it moved through the player's overlapping sensor ranges, depending on distance to the ship/planet/starbase throwing up the clear view circle. And I guess it would be made ineffective by Eyes of the Universe? Or maybe EOTU just knocks it back a parsec or two in effect.

As with all these ideas, the AI would have to be able to handle it, or it's just a player exploit. For example, the AI shouldn't bother buying cloaking modules if the player or a race targeted for conquest already has the EOTU achievement, or a heavy investment in whatever anti-cloak measures are available.

Small ships in DA definately need help, and evasion to me is the ticket. In DL, small hulls worked because ships weapons all fired at one target.

In Da that one huge hull can kill a whole fleet of smalls in one turn. This has essentially made small hulls useless later in the game.

What I'm saying is make evasion only really effective for smaller ships. IE that behomoth massive hull shouldn't be able dodge anything...

I don't think it needs to be a big effect, just enough to give small hulls a place in the game again. (a larger hull should be better, but not supreme as they are now)