2. Stan's Money Obsession Theory
This chapter by Prez Cipher.
Bill is based on the Eye of Providence on the U.S. dollar bills. What if Bill can watch through the Eye of Providence? Think about it. We never see any of the money Stan makes besides him counting and storing it, and he sure as heck doesn't put the money into himself or the Shack. What if Stan is trying to keep Bill from watching...?