just a note up above, heat pads get no where near hot enough to crack glass or melt plastic under normal conditions. I ran my flexwatt unregulated just to see how hot it can get because everyone has different numbers, i read 145 at the hottest, no plastic melted but they would kill a snake very quickly.

give my opinion on things, even tho i agree with everything else shes saying.

your questions
1. like she said pay attention to the snake, but also no harm in changing the day eigher, never had a problem switching a snakes feeding day.
3. depends on the snake, if they are just constantly trying to find a place to hide like going in your hoodie as you said, thier really not exploring and most likly stressed and taking cover. i would just handle in short sessions for now. after they get used to the flow of things they will just be curious about everything and explore, then no harm keeping them out as long as you want imo. just gotta pay attention to them and make sure their not stressing.

also I don't have a problem handling my snakes 5 minutes before the eat and alot of them i do. my normal practice is to clean their cages if needed and feed them after. so some are out of their cage 5 minutes b4 they eat... i don't see an issue. i leave them alone for atleast a day after, and if i do handle them a couple days after feeding, it only short sessions as stated b4 they need the heat to digest and all that stuff stated up above. wait til the lump in their stomach goes down (2-3 days) and they should be fine.

also don't be afraid to take your snake out if its in shed to clean its cage, its not going to die lol, just clean the cage and put em back in.

4.Flexwatt or just a store bought heatpad will work, and we can't stress it enough, regulate it.