1) Yes. EVs count for all pokemon. You just won't have their full effects. At level 50, ~8 EVs = 1 stat point
2) It helps
3) You bring 6, though you only get 4 in battle
4) Somebody else should answer this.
5) They have IVs (all pokemon do >_>). You can EV train a level 50 too; just fight low leveled pokemon so that you don't level up, and when you're done deposit it in the PC. Exit, withdraw, and vuala. So in other words yes.
6) Yes. You can find them
here, though the jist is:
~Species Clause
~Item Clause
~Name Clause (two pokemon cannot have same name; pokemon cannot be nicknamed other species names, like Gliscor named Lucario; no inappropriate names)
Ban list can be found in the link and original post.