There's no limit to your hand size. Yes, if Durkon wants to spend every other turn resting, he can take the whole deck if that's the kind of thing that makes the game fun for him.
Right, if two or more people don't touch their nose, then the shtick has no effect.
No.
Right. A monster can only support the top-most monster that it can support. Both Redcloak and the other goblins will support the top-most goblin (the ninjas) and Redcloak will receive support from only the ninjas, since it's the only other goblin in play when Redcloak comes down and since it's the top-most goblin that the ninjas can support.
No, they're still supporting the ninjas. However, if the ninjas are defeated, then the goblin's support will switch to Redcloak.