I'm sure all of my thoughts have already been mentioned somewhere in these forums... I'm not seeing a dedicated suggestions forum so I assume they are all in general somewhere.
Just suggest whatever in the general discussion forum. If you're worried something you're suggesting has been suggested just try and give it a quick search, then necrosis the thread I guess. (Unless the thread is just really off tangent in which it'd be better off for you to create a new thread) Popularly brought up suggestions may get the silly joke sigh from some of these forum oldies (like suggesting shields, experimentals, etc...) but don't worry, we're normally not too stingy of that kinda stuff. Just post whatever you want. =)
Thanks for the reply. Currently I have one suggestion (and technically feedback) about the Galactic War mode. I have found this mode to be extremely linear. Certain changes can definitely improve replay value, such as: Make each owned system create/own a tech that is smaller scale than the current techs (ex. build light tanks opposed to basic vehicle factory). Allow the player to choose their own techs in this manner. Make the AI fight back in the galactic war map Make the AI start with one spot as well and grow each turn. This makes your decisions per turn more meaningful. Have a capital system that provides a super power (such as a sub commander, halleys, etc...) I found that when I had possession of a sub commander, halleys, the orbital defense stations, and anti nukes... AI had no hope in beating me.
These are all good ideas, also as it happens @jables has mentioned Galactic War is on the hit list for some tweaks probably over the summer.
Keep an eye out on the PTE sticky post too. As the devs get into GW changes they'll be going out to the PTE first, which will be an excellent time to try out the changes being made and suggest tweaks or additional changes.