Here is a much more clean and polished solution to all the riddles
http://www.gamesradar.com/pc/f/batman-arkham-asylum-riddler-...Obviously this is not my guide I am simply posting the link
EDIT 11/13/13:
I can confirm(played the game 3 times now) that there is nothing that is locked out. If you have ANY issues getting to any place I would be happy to walk you through an area to the best of my ability.