ok so heres a cutaway of the n52
as you can see the drive belt is at the very front of the engine. behind that is a metal timing chain cover which is sealed to the side of the cylinder block/head.....with that being said, there isn't a snowballs chance in hell that belt is getting inside that engine. so dont get over worked and dont let the dealer bend you over!
on a side note, i dont know what the deal is with the "special" loctite your talking about, but if you want a bolt to stay there is nothing more i would trust than red loctite.