Do you get the "cpu overload error" no matter what you do?
I too just bought a mac mini 2.3 i7 and upgraded to 10 and I was getting the cpu errors. Actually I was also getting it with PT9 which is not supported with 10.8 so I upgraded to 10 and it did not resolve the problem. The issue is ML 10.8 is just not as stable with PT10 yet.
Many have went back to 10.7 and say there problems went away, but we are stuck with 10.8, Be sure you do all the normal stuff like spotlight disable, 7200 record drive, turn off wifi etc., I fixed my issue by putting my buffer at 128. For some reason tracking at a 64 buffer throughs out cpu errors even with the cpu meter at 3-5%.
How much ram do you have? I have 4gb and I have 16gb on the way, I read that someone fixed their issue with more ram, because ML is a hog, plus the hd4000 graphics steals some ram also.
Today I upgraded to 10.3.4, which just came out. Its a full installer and might fix some of your issues also. I wish I could track at a 64 buffer but a big plus is PT10 had low latency monitoring with my apogee ensemble.