I've been playing for about a month, and I'm hooked. GFG.
Some suggestions for gameplay. Some have probably been posted, but I figure a few might not be so.
1) Human spawn: Make it so any human (or alien) standing on a spawn node is incinerated when the next person spawns in. Hate it when people block the spawn. If killing is too much, maybe bumping them out automatically, or making the node so it cannot be entered, only exited.
2) Player takes damage for damaging their own structures. Could even make a server setting where an admin sets how much damage is done back, say 2 to 1 or 3 to 1, so they die before they can wipe out a structure. Maybe ignore the damage if an enemy is within x feet from said item. Probably getting too complex here.
3) Make it so multiple deconning without constructing becomes impossible; save this state even if the player dies. For example, start a builder with 3 points, he loses x points every time he deconstructs something, and cannot build once he gets to 0. Make the reactor worth 3 (-3 to deconstruct and 3 to build), turrets 1 and teslas 2. Although one problem with this method might be a team coordinated deconstruction - construction; the deconner in this instance would be punished for working with a teammate.
4) Do not allow players coming into a game late to decon key structures until they have been playing for x minutes. Most griefers want to just jump in and cause havoc, not wait to do it. Punks.
5) Some servers have a wait time to allow people to connect to a new game. I'd also like to see a wait time for people to join a team and enter the game. Maybe 'gates' a la Team Fortress Classic that give teams a minute to spawn and maybe move 2 or 3 structures to better points.
6) Give the humans a lay down ability. I'd like to see this one mainly because of friendly fire. If you lay down the people behind you can fire as well; this would be balanced by leaving yourself open as a target. Similarly I'd like to see Tyrants and Dragoons be able to run over Dretches.
7) Make the defense computer interactive so you can set priority targets. If 3 dretches and a tyrant are coming in, let a human set the turrets to either ignore the dretches until the tyrant is no longer a valid target or vice versa. I'm not talking about making it attack specific targets, more of a few generic options like attack strongest target, attack all targets, or attack weakest targets. Although I guess this adds to the strategy of the game... dretches running in with a tyrant can pull some of the heat off the tyrant long enough for the tyrant to cause some damage. Just an idea.

Allow for two overminds / reactors. But only allow one to be on, and make the off one self-destruct after x seconds. I think this would encourage base moving.
9) Make the grenade a little bigger. It's very hard to see. Or maybe I'm just whiny.
That's all I can think of right now. Comment away!