To add, the P8700 is pretty efficient and low-power as Core2Duos go. If I remember correctly, it's a 20 or 25-watt part. (Compare to 35-watt for the i5-3210M in the 2012/Ivy Bridge mini).
It shouldn't really take much to cool it, so even if Apple (mistakenly or intentionally) did something to reduce that cooling ability, it should still be pretty efficient, especially after the paste job you did to it.
I wouldn't worry too hard, as Byrd says, the minis almost never overheat -- and the only reason one of them would is if it were getting old and the paste was never reapplied or it was reapplied incorrectly.
Fortunately, the way it would fail is that the chip would get slow and then shut down before any actual damage was done, giving you warning that it's time to do some maintenance.
It shouldn't really take much to cool it, so even if Apple (mistakenly or intentionally) did something to reduce that cooling ability, it should still be pretty efficient, especially after the paste job you did to it.
I wouldn't worry too hard, as Byrd says, the minis almost never overheat -- and the only reason one of them would is if it were getting old and the paste was never reapplied or it was reapplied incorrectly.
Fortunately, the way it would fail is that the chip would get slow and then shut down before any actual damage was done, giving you warning that it's time to do some maintenance.