Thanks for taking the time to give feedback.
About the shipyards.
I have no idea how the "add 3D models to the 3D engine" magic works but if it starts with a .3ds or .obj file then it's possible for me to send such a file type with the shipyard model.
My original line of thought was that the "extra" shipyards sounded more as factory modules added to the basic shipyard structure then separate constructions. If you look at the model you'll see on the side, four such modules [in this case of the same type]. So we can call the model "Orbital Drydock" instead of "Shipyard", the modules are the "factories" where the basic ship components are built in-orbit. The icons for the "extra shipyards" [like: Industrialized Organic Assembly, Orbital Incubator, Bioneural Modification Unit, etc.] would be represented by modules that get attached to the side of the Basic Shipyard. Also the icons will feature only the module and not how they look connected on the shipyard structure. Just my two solar cents.
The Concentration Camps
The most cost effective icon would be a pair of handcuffs. At the moment I don't have an idea on how to model a camp and keep the view ground based. Maybe it'll come to me in the future or possibly someone else will create something better. Well see.
Imperial Palace ?... *cough* Administrative Hub *cough*
You're right about the epicness level. It looks a little better from the aerial view, designed it without the "must look best from ground level" theorem. Perhaps another try will generate better results.
PsiCorpsHQ
You know what they say:"When in design doubt, use concentric circles!".

Hmm... Salient points, I'll see what I can do about the "creepy" factor.
Err... since other work is priority... updates will be later during the next week.