Yes you should be able to pop or probe a baby bp, if you have an experienced person doing so.

I agree that viv size is WAYY to big. You want some very small to start out with. I believe the tubs they usually start out in are approximately 6" x 16". Smaller is better.

I would prefer to get a snake that has excellent feeding records. It gives you a bit more assurance that the animal has eaten.

I know as adults, feeding weekly is fine. Offer smaller prey items, usually no bigger than a small rat.