EVs are NEVER split. So using EXP share will not reduce the amount of EVs a pokemon will obtain, the same goes for switching out.
This and that. One other thing: Things like the Power Items and Pokerus effects only work if the Pokemon has them. So, in the following cases...
-You lead with a Krabby holding a Power Anklet, then switch to another Pokemon. Krabby gets 6 Speed EVs (two from Basculin, four from the Anklet), and your other Pokemon gets 2 Speed EVs (from Basculin).
-You lead with an arbitrary Pokemon holding a Power Anklet. Krabby is in your party holding an EXP. Share, but never enters the battle. Your lead Pokemon gets 6 Speed EVs and your Krabby only gets 2 Speed EVs.
I claim to be the official Porygon2 of the Pokemon Black 2 board. Scientist MileRun: WaRy associate