Unfortunately, seeing as you've done the only known proper way of installing PR onto the Steam version and have the latest available FoC patch, those may not be your issues. Mostly, issues with that are usually improper installs, installs directly into the game directory, or a lack of patches. However, the AI in Space Tactical mode should work just fine. Land structures should be constructed as usual. There was an issue somewhere that prevented the Galactic AI from building the Space Colony level 1, and therefore all other space structures. The issue Ghostrider and DaveAshton mention is solely for Galactic.
