Never say "waste money at a dealership". No dealership is interested in whats in your wallet. Their concern is to address you any preventative maintenance to give you longevity of owning the vehicle. You may think they are trying to rob you out of money, but any shop you go to that's well known, labor rate is $100/hr. I say might as well get to the dealer, knowing that they will warranty their repair and knowing that the technicians are certified to work on your GM vehicle.
Your issue has an electrical problem as Coby and I can tell
I wouldn't say weight has an issue for the short, but it causes the short to occur. The passenger air bag module does not activate until the seat has recorded at least 30 lbs to see a person is present.
Do not fool with the SAS equipment without removing the battery source for at least 10 minutes. For your fuse blowing everytime, are you using the same amp rating fuse? Do NOT use a higher amp rating fuse, thinking that will solve the problem. You have what technicans call a short to ground circuit. Meaning as soon as you complete the circuit with a fuse, it overloads and pops the fuse. If you do not know what your doing, you may cause wires to melt and you "will" have to take it in to the dealership for soldering of a new circuit, and that's $$$ for labor.
Not trying to procrastinate you or belittle you, just that you should not attempt electrical repairs if you have no understanding to save you trouble and frustration. Yet alone, let one simple repair turn into a nightmare with a whole new air bag module and that's $$$ plus a report on that vehicle to the DMV and carfax that a new air bag module with BCM was replaced. That's not good at all to see that happen. It really reduces the value on the vehicle.
After all of this, have you at least looked at the power window relay? If its stuck on the single throw all the time, it stays on "all the time" and that would be my starting point if you were a customer at a dealership. I would check the battery first, then check the relay.