Another thing that may be affecting his "confidence" is that he's housed in a 75 gal. tank- that is pretty huge for a young BP. Without seeing his set-up- there's no way to know if you have enough hiding places for him so he feels bolder, but the behavior as you've described it suggests to me that he lacks confidence- because he shows interest but cannot "close the deal" & backs off, especially if the rat "boops" his nose. What size is your BP & what size rat are you trying to feed him?
Another thing- when a snake refuses a meal, don't keep on re-offering, as that just stresses them out. If he refuses to eat, wait until it's time to feed again. Most feed young BPs weekly, but you're feeding every 2 weeks, so adjust accordingly, & if that keeps failing, go to longer intervals. And as I said, without seeing your snake, for all I know he might be over-fed or under-fed.![]()