IE - If I try to EV train a baby snorlax for HP by giving it an Exp-Share and having my Salamence fry lairons, will the both get the EV's, 2 to salamence 2 to snorlax???
Yes.
If you train a Pokémon and another Pokémon is holding the Exp. Share, then both the Pokémon get the EVs. The won't won't be split. So if Salamence KOs a Lairon and a Snorlax has an Exp. Share, then both will get two defence EVs.