A couple of things that I noted about Core Temp vs. True Temp. I found that (at least on my Q6600 B3) that the TJMax was identified as 85* on Cire Temp, and 90* on True Temp. My research indicated that the TJMax for the Q6600 B3 was actually 90*, so I ended up having to adjust my offset in Core Temp to reflect the same readings I was getting in True Temp (the ACCURATE) app.
It might be possible that if a negative entry was in your core temp offset, you would end up with temps below ambient (impossible, otherwise). I would check the TJMax for your CPU, and ensure that it is refelected accurately in Core Temp, and if not adjust it up or down to the correct threshold.
As far as my H70's go: I used a razor blade to shave my TIM off, and then used 99% isopropyl to remove any residue. I then lapped it to a mirror shine
It wasn't easy to lap it, given the radiator being attached, but here is what I did:
1) I used a fairly large sheet of glass as my base. I had an old mirror that was sufficient size, so I used that (it was about 24"x24").
2) I started with 800 grit wet/dry automotive sandpaper, and laid it down on the glass. I place a towel over half of the mirror, and ensured that the radiator was well cushioned by it. I poured some water and JUST A DROP of liquid dishsoap onto the sandpaper, and then sanded in a figure 8 pattern for about a 30 seconds to a minute, just to get rid of the burrs. I had to add a little water every little while, to esure that it kept sliding with only a slight amount of resistance. You have to be very careful to keep the HS flat against the surface, since any angled pressure will result in the edge of the HS tearing the paper (even moreso 'cuz its wet)
3) I progressed to 1000 grit, and followed the same process for about 2 minutes...maybe less.
4) I moved to 2000 grit for about the same amount of time, looking at it every now and then, to ensure it was a nice, even finish. You will not get a complete mirror finish this way, but it will actually be fairly reflective, and all you will see at the end of this is a sort of satin shine.
5) I then used some brasso to buff and polish it to a mirror reflective shine. It literally looked like a mirror, without any refraction or distortion...absolutely gorgeous! The toughest part from that point was ensuring that every little bit of polish was removed from the HS surface. It took quite a bit of elbow grease and a lot of clean, lint free white cloths. Only after I was absolutely certain that no more polish remained (no black/discoloration of the cloths..at which point, I continued doing it for about the same length of time again...) did I being the process of installing it.
6) I have read all kinds of different views on the application of TIM, and I have played with pretty much all of them, including the "BB sized" drop in the center of round HS surfaces, but after inspecting the results, I decided to go back to my method. I used a "larger" BB sized drop of AS5 in the center, and then spread it around to cover the entire surface in an even, REALLY thin layer, using another razor blade like a dry-wall trowl. That one dollop managed to cover the entire surface, and even had a substantial amount left over on the blade when I was done.
I dunno what your guy's take on this whole process is, but I am/was happy with the result..