For starters, cohabbing ball pythons is not generally recommended. There are people who do it, but at the very least they need a larger enclosure with more hides and stuff in it than they would if they were living individually, and they definitely need to be fed separately. Your tank looks like it's an OK size for one snake, but not for two (which should not be taken as an endorsement of housing them together!).
So if funds are tight for now, I would make saving up or scrounging for another tank some kind of medium term priority so they can each have their own space.

For feeding, they need to be separated so they don't accidentally hurt each other. Give them the mice one at a time. If you can switch them over to eating frozen/thawed rats that will make things a lot more convenient - one appropriately-sized prey that you can keep on hand without having to keep shopping for live, and dead prey can't bite.

They don't need baths unless they go squirming through piles of poop and are covered in it.

The rock hides are fine; better than the half logs, because the half logs are too open. A variety of hides is not a bad thing IMO, although others here will recommend two identical ones.

For humidity, cover as much of the screen top as you can with foil or saran wrap to reduce the amount of open screen through which your humid air can escape.

Reptile carpet seems like more trouble than it's worth to me, although I think there are folks here who use it. Coco husk bedding is a good choice for retaining humidity, but only if it actually has some moisture in it to begin with. It's very absorbent though, so you can spray it down pretty liberally or even just pour some water into it (not so much that your substrate turns to mud or soup though!) and that will help keep the humidity up over the course of the day. It's also very easy to spot clean in; you just scoop up the area around the mess. If you use paper towels or reptile carpet, you have to pick up all the furniture and replace the whole piece.

The belly picture you showed is a little hard to see anything much in; it could be a minor burn, or it could be just pink belly as a result of heading into shed. If you really think it's likely to be a burn, a vet trip is a good idea.

It sounds like your temperatures are good enough, so you don't need the heater on the back wall. Since you already stuck it there, you might as well leave it as a backup heat source just in case, but your temperatures sound fine just with the lamps. Although speaking of lamps, despite what the marketing tells you, snakes actually can see red light. It's not an emergency, but at some point you might get a ceramic heat emitter, which is basically a bulb that emits heat but no light. It can go into the same fixture you already have.