I've got systems that have run in excess of one year without issue using ASII. I take care to blow the dust out now and then, but nothing more. I have noticed odd patterns on both the chip packaging and heat sink base outside of the die region that could be described as "ghosting". These appear to be the result of some volatile component of the ASII, but haven't changed performance by my reackoning.
As to you "PS", the answer is yes if the 24 pounds is centered within the "box" defined by your corners.