RUMBLETiGER
Adventurer
for the purpose of this thread, lets assume pre-enhanced critters come to you with official feats, simply because I want to use this info as a player, not messing with my DM.So beside the point. Imps, Quasits, Mephits etc. have 3 HD before they ever become a familiar. So they have two feats right out of the gates. Now whether those can be changed from the ones given in their MM entry is an entirely different question - but if they CAN, you have two feats to work with. Which can be used for Bind Vestige and Improved Bind Vestige, for example.
However, once the pet gains HD, that sucker's mine to do with as I will! Training a set of baboons to draw Binder symbols sounds legit to me. I just need to get a pack of Handle Animal Fleshrakers to draw with their big toes.