1) Mt. Battle has a counter to the far right of the main room where you can exchange earned coupons for prizes.
2) No, you cannot SNAG non-Shadow Pokemon. Ho-Oh can be obtained, but he's actually
given to you, after you beat Mt. Battle's 100th platform.
3) Unless I am mistaken for what you mean, mothermole, those are hold items. Otherwise, explain clearer
I am a signature... But what am I if my master does not type anything on me? Wait...What am I saying, 'master'? I choose my own destiny... Ah, screw it! I'll stay in this bar for a couple of more years...