1) my first question has to do with EV Training: if i trade over a fully ev trained pokemon (i.e. 510 ev) to a different game cartridge will that pokemon lose all of its ev's?

2)my next question is a moveset for Rayquaza:
Rayquaza@Leftovers or Petaya Berry or Salac Berry
Modest | Air Lock
Attacks:
Dragon Claw - since its Rayquaza'a most powerful attack with STAB I intend to use it on those pokemon which the other attacks hit neutral
Ice Beam
Thunderbolt - boltbeam hits alot of opponents for super effective damage
Flamethrower / Surf / Crunch - I'm not sure which move to select for the last slot, thats where I need the help - state your choice and why or if you feel i should have another move in this slot feel free to suggest it.
(no i don't intend to use rayquaza for competitive play, just to have one fully trained on the side, like I do all starters and legendaries, it doesn't mean i intentionally use them)

thank you for your time and input

1) No. Pokemon keep EVs when traded.

2) Pokemon rating/suggestion questions should go in the Advanced Generation Rating Center.