Advice for pacing Quant (50/51)?

Hi guys,

I'm doing well in Quant (50/51 consistently), but I'm running into serious timing problems and I have a couple questions:

1) How bad is it for your score if you end a section poorly (say, you were getting all of the questions right, then got 3 of the last 6 wrong or something).

2) How do you guys pace the Quant section? I've tried to roughly keep it to 2 minutes a question as long as possible, but once I hit the hard questions I slow down considerably and am reluctant to answer questions without being 100% sure. It's pretty commonplace for me to have 3 minutes left for the last 3 questions and have to make educated guesses on them.

I'm taking the GMAT in 10 days.

Thanks!