The description of Rachel turning into a spinywhahoozit could stand to have more emotional detail, but the visual detail is good. Also, I can buy that her attack on Spike happened pretty quickly, but Fred and / or Knox would've had time to do something, like yell (Knox, "I am going to KILL the guys in translation!"), grab something with which to whack Rachel or hit an alarm.
Person Unconscious but Possessed? Yep, that's exactly the sort of thing that happens on Angel. I wouldn't put it past Wolfram and Hart to have covered that in the employee health plan.
I could stand to see more of Fred's speech patterns. Is there anything ginourmous in there?