A680

150 ft. round 1, 300 ft. each round after that.
Quote Originally Posted by Minimum Forward Speed
If it is too high above the ground to land, it falls straight down, descending 150 feet in the first round of falling. If this distance brings it to the ground, it takes falling damage. If the fall doesn’t bring the creature to the ground, it must spend its next turn recovering from the stall. It must succeed on a DC 20 Reflex save to recover. Otherwise it falls another 300 feet.
A683

Yes. I don't know about Githzerai, but for drow:
Quote Originally Posted by Drow
Spell resistance equal to 11 + class levels.
And as you quoted, bloodline levels are class levels for the purpose of "any
character ability based on his class levels," such as SR.