1: Misty (I always start with charmander or more often, pikachu)
2. no-one was that hard except red, destiny bond and focus sash always sealed the deal when you got stuck, otherwise clairs kingdra
3. Tate and Liza (how many times did they beat me?)
4. Hmm... I don't really have one at the moment. Don't own the game myself so I haven't faced all leaders.