Don't know why Mime as a job has always interested me. I suppose it goes back to FF7 and Copycat, where you could copy Knights of the Round back to back for some pretty sexy numbers.
Anyhow... please understand that this thread is really for fun, not so much a debate on whether it's be a likely or viable class (though I'm sure I'll get those replies too)
So anyhoo, here's my daydreaming thoughts -
1. Can only Mimic Classes/Jobs that have already been learned.
For Example. You can't mimic a monk in your party, if you don't already have Monk leveled.
2. You can only Copy one class at a time.
You can't heal and dps and tank. I picture a tether, like the one from Cover, indicating which player you are currently copying.
3. You can only copy living party members.
If the White Mage dies, and you opt to mimic a healer, you must mimic the Scholar who is alive. If the Warrior dies, you must mime the Paladin.
4. Restrictions on Job specific abilities.
Either allow access to some or no Job specific abilities. I think the job should default to DPS, and that Healing and Tanking be somewhat limited to niche situations. Access to Sentinel, but not Hallowed ground, Cure II but not Benediction.
Anyhow, can't sleep, may as well daydream. If you'd like to with me, feel free to reply.