Just an FYI, making your threads easier to read will get you more replies. Many people skip over threads that are one giant run-on paragraph....
Now, to help with your questions:
1) I would want to make sure she's eating. If she'll accept mice stick with mice til she's eating consistently, then try to switch
2) I would offer 5-7 days after you last offered
3) As for the bath, where is the stuck She's? Eyes, vent and tail clear? Is there a lot stuck?
4) honestly, the best trick for good sheds is good, consistent husbandry. Not just bumping humidity while in shed. Of course, bumping helps, but new sheds start from the tim the old akin comes off. Just keep your husbandry right and the clean sheds will come. Dont waste your money on commercial shed products when its as easy as proper husbandry.
5) I've never to do any scenting or braining, so I'm no help there.
When it comes to getting young snakes eating the issue is most often husbandry or stress. Your husbandry seems like it's pretty good, so could it be stress??
Are you handling the snake?
Maybe adding some more clutter might help the snake feel more secure. Are the sides covered with dark paper or cardboard or anything? Making BPs feel secure is very important.