No problem at all!

Yeah, those temps are probably off then, but he should be fine until you can get a digital thermometer. I know what it's like living from paycheck to paycheck, it can be tough. I also know things are a little more expensive over there on the west coast, but a great place to get a digital thermometer for cheap is either walmart or home depot. You can find a good thermometer/hygrometer for only around $10 at home depot around here, so you could look into that.
Yeah, I would say switch them if it's not too much trouble. If you have the funds, I would also suggest getting 2 cheap lamp dimmers at home depot (I believe they're only around $10 a piece too). If that's too much though, you should at least get one to hook up to the cool side UTH so you can turn the temp down, and then get another one or a cheap thermostat when you can. I personally use the hydrofarm one that you can get on amazon for $25, and it works great.
Also, the washcloth isn't a bad idea and I would keep them on until you get dimmers or a thermostat, but you can actually use aluminum foil tape (also found at home depot/walmart haha) to cover the sticky side and to attach it to your tank. It conducts heat very well, and is much easier to remove if you ever have to.
Yes, he has some folds, but actually my ball python has those right now as well since she's also on her fast. It is a little underweight, but you don't have to worry until he starts feeling noticeably lighter and getting more of a triangle shape to him. Then you might want to think about bringing him to a vet to have some tests done.
He looks alright to me though. Just keep offering every week, give him the 2 hides, and try to get the temps sorted out! I'll bet you'll find that the temps and the hides were your main problem, and once he finally settles in and decides that he's hungry again, he'll be eating fine. He's obviously been eating alright for several years prior to when you got him, but I know, it's hard not to worry!
Sorry for the long reply, and again, I hope you find some of this helpful!!