You'll definately need more than 2 hinges on the elevator. The SE is an aginle bird and would dispose of 2 hinges rather easily I would guess. I would make sure you put the same amount on that was originally supposed to go on. If I remember correctly the elevator had 3 hinges on each half for a total of 6. You might need to get a slot cutter if you are having trouble re-slotting your hinges. Or maybe someone in your club would have one you could borrow.

As far as the rudder is concerned, I'm not quite sure what you are asking? Has the ridder hinges actually been glued? If so then I would assume that you are going to need to remove it to do it correctly. If you haven't mounted the rudder yet then you should be fine. Just wait until after you've glued the elev on, then mount the rudder.