Thank you for your feedback! :D It's awesome to see that the game works on less beefy computers. That was one of the intentions we had while making the game. So there are no guns located inside the building. When items on the mini-map appear to be inside the building, it actually means that they are on top of the building. You can jump up walls by pressing space in air while you're near a wall.
We've been working on a mode where there are no citizens. That mode will be released sometime in the future :)
As for the SWAT force, unfortunately we've decided that adding a SWAT, police, or military force will defeat the "hero" aspect of the game.
Eventually we will give the citizens smarter A.I. if the audience for this game keeps growing.
Cheers!