Welcome to THF the fong.
wondering if my temps and voltages were within safe limits
The tcase for the Q9550 is 71.4 C and Vc is .8500V - 1.625V. LINK
That being said I have run my CPU well over 1.4V and so far it still lives. My 24/7 OC is 3.83GHz with water cooling @ 1.30 Vc and as pointed out to you already your temps are fine for the OC you have. I do not like to go over 65 ~67C under-load but that is just for my peace of mind.
Since the only common component we have is the Q9550 I can tell you my experience with my M/BD was the higher NB V I could run the lower I could set my Vc. I also had to tinker with the PLL and VTT voltages for stability with my M/BD and ram timings had to be set manually. I left all the GTL voltages on AUTO.
Thou for the OC @ the bottom I had to adjust those as well but that was just to see if I could get a 500 FSB OC. It was Prime 95 stable for the 30 minutes I ran it.
I found a review, LINK
, for your M'BD that has some pretty good info
regarding its capabilities which you probably already know.
Hope this helps you.