You can't burn out that processor unless you remove the HSF (and even then you may have a tough time doing it). At worst it gets to 100°C and then it shuts down. I know because the fan stopped working on mine and it shutdown a few times before I determined what the issue was. Since that happened, it has been running non-stop in a VM server for more than 2 years. 70°C is nothing to worry about for that CPU.
Could this be the reason why it is getting so hot? Or is this temperature normal for the Q6600?
Temperatures on mine are 3°C lower than yours; I used a very thin layer of AS5 and it had a few years to cure. Core #0 runs a couple degrees warmer and that's normal. You provided Core temperatures, but what is the ambient room temperature (my room is at 23°C). Maximum temperature is reached within a few minutes and it won't get more than one or two degrees higher after 12 hours or more of Prime95.
I stopped running the test after 4 minutes as it reached 70c at 100% load. I starting to think that maybe I need to re-apply my thermal paste. Also another thing is that at approximately 30-40% CPU usage the temperatures sore upto 60-70c.
Reapply the thermal paste. A small pea size is enough, but I prefer using a rigid plastic card and spread a very thin layer. Thermal paste is used to fill the gaps, not to isolate the CPU from the HSF.