I will say that when I got 9.4, my sensitivity was on 10 or 11. I'd say anything 10+ should be good as long as you can get used to it. I do think ReapZ uses 20 in his 8.65, but you'd have to ask him

for me it was on and off for about a week, no more than like 30 minutes at a time. As for the number of attempts, I would guess around 500-600

The thing at the end I hardly ever have a chance at even going for because I just fail everything before it, but seeing the run you submitted, you at least got it :D

Fixed it :)