I expect this to lead up to Gordon taking over for Sanji for good. Especially with the Baroque Works arc coming up.

Yeah, same thought just crossed my mind; DM will eventually take over GMing, and Gordon will start playing Sanji full time.

This could explain why she is only named DM.

It would also explain other actions, though again I'm expecting DM's actions will make her not liked by the group and she will get pulled back in as Robin(after playing robin as a pet npc well she gm's the game)

I dunno, actually. Sanji spent a lot of time in the Baroque Works arc out of sight, then showing up and saving the day.

I thought she was called DM because she used to be their DM.

Those are her initials. One Q+A mentioned what they were but I forgot.

GM is named Gordon and hes playing Sanji. I find this funny proceed.

Does it require anything special in Pathfinder to bite someone who is right in front of you?

Really asking; I know I sound like a broken record, but I'm not familiar with the system (played some D&D 3e over a decade ago =P). The systems I have played do allow people to try a bite, it is just usually its a really stupid way for a human to attack (low damage, risk of injury).

However sometimes grappling makes normally difficult targets much easier. For example, if two humans are grappling face to face, the usual -3 penalty to hit the groin doesn't apply to a knee strike.