Legendslayer, did you know that taking the grid snap off of your maps is really unhealthy for them. I noticed on your Rise of USP map that just about everything in your map was unsnapped from the grid. No scolding meant here, just a tip for this SP you're working on. This thing can force you to make much more simpler maps simply do to BSP errors, and with you building your skills at making a believable and appealing environment your not gonna want hitches so soon during the building of a really detailed map.
If you want to add decorative objects and details that look convincing, you should probably use semi-solids for those, as they take cuts onto themselves instead of creating more on surrounding surfaces. Very early tips that can enhance your advantages towards a good map, and as you build your skills, I'm sure your knack for creative story and environments will come together very well.