Bonzo said:
2. Can heroes also be declared as defenders?
Sure thing
Bonzo said:
3. Can I combine Gandalf with "Sneak attack?" So bring him into game, let him do his damage and then take him back onto my hand? Or do I have to discard him after the phase then?
You just brought up one of the most discussed topics so far (check BGG). My opinion is that Gandalf should not be able to use his special ability with Sneak Attack or that would be almost a quest breaker all the time. So if you Sneak attack him just can use him in one Phase (his stats alone are just awesome) and then back to your hand. If you pay the 5 Resources, then use him for one full round but then discard.
This is almost sure a topic in the first official FAQ though.
.
.