Answer 1

Is there a specific direction you have to look? It seems kind of buggy, like the same action will have different outcomes.

Answer 2

It probably is buggy, but the idea is that the wooden blocks hide when you look at them and shown when you're not looking at them. The bookshelves are the other way around, so they hide when you're  not looking and show when you are. And if you are on top or below a block it will keep the state it last had.

Answer 3

I have no idea what's happening in there but I bonked my head everywhere and it ended up working.