Say, when there is a half/full step bend on the 10th fret of the B string, pick/play 7th on the high e, pull off 10th to 7th on the B again.. how do you do the pull off? What fingers do you use for the pull off? Pinky and index or ring/third finger and index?

Generally the third finger has better bending control so I would probably go with hat depending on the context though.
If you have the power to do it comfortably (and accurately) with your pinky then power to you, but I would honestly suggest using the ring finger. It all boils down to the context of the lick.

Current Gear:
Gibson Boneyard with Bigsby
Gibson 93' Explorer W/Nailbombs
G&L 93' Legacy W/Noiseless
Gibson 95' Doublecut W/Angus Bridge

Mesa Stiletto Trident
Bogner Shiva
Mesa 2x12 & 4x12 Cabs