I really support Gastro Acid. Most of the top-OU Pokémon rely on their ability, and can be really hampered by its removal. Unfortunately this removal is nullified by a switch-out, but it could indeed force switches.
On the other hand, I find Me First not so useful. It's quite situational, and while CAP6 can outspeed many Pokémon it is meant to check (Tyranitar, Scizor, Revenankh etc), most of the times the STAB attacks will do more, even taking into account the 1.5 damage boost. So, I really dont see the point besides not allowing it.