Gandalf's staff is incredibly good. At first I was thinking he would only be able to contribute 1 resource to the top card of your deck, but with the staff giving him a resource he can play for any 2 resource card, so if you want Steward of Gondor in a deck without leadership and songs he could get it. Even in the first round if the Staff was payed for by 2 other heroes, he could then use the staff to get a resource and get SoG if it was on top of the deck.
Crazy stuff I say!
@Bullroarer, why you say no to Expert Treasure? Once a card is removed from the deck the next card should immediately become face up. It's a passive effect that should take place before the response.
From what I experienced so far there are going to be some timing issues like this while playing Gandalf.
Single hero will be a worthy challenge. Getting him with Treebeard + ents and Radagast with some eagles might be pretty interesting. Since, they are neutral allies that can provide some resources.