Hi there, information here "mime-jr" (<- here was a link...)
It is not bug, as it will always asking you for evolve if you have mimic move. It mean he cna evolve even if he level 100. Similar case with tangela or any pokemon requirment specific move to evolve.
Everstone implemented and you can get in blackthorn city (same place with dragon member medal, not quite sure)
I think thats not correct, in the original games, there is only evolution by level up, when the Pokémon knows the move, not everytime he gains experience points.
The Problem with the everstone is, I'm in Kanto so it is a long way I have to go, to get one everstone... or is it possible to get an everstone in the Dig-Spots?