Okay, it's your first homebrew so I'll try to not be too harsh. (plus you make me discover "standard action")
Prereq: Asking for an average of ability is unique I'll give you that but I don't see the need. In addition ability score rarelly factored in Prc prereq because you don't always control them.
Table: The code for the table can be found here or you can use that site.
Second your Bab and save are weird, they normally follow precise formula. Bab is either 1/2, 3/4 or equal to class level. And Save are either 1/3 or 2+1/2 class level.
Your missing the class Hit dice.
proficiency: does it mean that they lose any proficiency they have before ? Can they mime exotic weapon and use them ?
Spells: That's way too short. Look in the Dmg or the Srd to see the standard format used to progress spellcasting.
Skills: You give a skill list but no skill points.
Mime: Lot of problem there.
-You should give example of DC for each type of item or creature.
-Need more detail about the item create. It is visible ? can it be destroyed , Can you create item of any size ? How long do they last (this is important) ? Can other creature use them ? If you create a creature does it obey you ? Do any item dissapear if you go to far from it ? can you create multiple item at the same times ? If you create an inteligent creature, can it come with class level ?
You need to put limit and guidline on that.
Damage reduction: That's original. How can an opponent know that he can mime a weapon ?
Spell resistance: Okay why not.
Oath: okay, flavorfull at least. Maybe add the need for an atonment spell too. Do you broke the oath if a foe use dominate person on you and force you to speak ?
painted face: Flavorfull but need a mechanical impact. Penalty on disguise check perhaps.
Mime curse: That need more detail and is way too powerfull. You need to stat if the creature get a save to avoid the curse, what sort of control the mime can have on the cursed creature ? how many cursed creature can it control (based on Hit dice like turn undead coul work) ? Does the curse limit a creature action (only mime ability or anything) ? If speaking broke the curse what's stopping the creature from speaking immediatly to get free ?
Master mime: Yeah, lack detail too. What do you need to do to redeem a circus freak ?
For a first try it's not too bad, but it need lot of work. that said I like the concept.