Knight in front of fianchettoed bishop? What happens after castling?

I’m not very familiar with hypermodern playing style, so I’d like to understand better the ideas behind it.

I’m wondering about the typical feature of fianchettoing the Bishop. There are two doubts I have:

1) Is it a good idea to place a knight in front of a fianchettoed Bishop (such as in the Pirc defence)? I think it may be a useful weapon to create powerful combinations, since moving the knight might discover the bishop attack. However, the Bishop is still blocked and I end up with losing a tempo, since I develop two pieces (Knight and Bishop), but only one of them actively controls some squares on the board (unless I move the knight, but that’s the tempo I lose). Am I getting something wrong?

2) If the oppent castles on the same side of the fianchettoed Bishop, doesn‘t this keep it a little out of the game?

Thanks in advance!

That sounds all quite reasonable indeed. Thanks!