With a good thermal paste, wouldn't a 'rough' cover for your CPU and heatsink base actually improve heat dissipation because you have more surface area? Or is there just no paste that's as good as basically touching everywhere along the surface?
The issue is that the metal CPU heat spreader and metal heatsink base conduct heat MUCH better than any thermal compound, so the problem is not getting the heat to the thermal compound (as you suggest), but rather the heat passing through the thermal compound itself. Thus, the thermal compound layer is the bottleneck in heat transfer, and the thinner the thermal compound layer, the better. The smoother the CPU and hs base, the thinner the thermal compound layer can be.
Give it a shot, your CPU will shut off at 100c, hehe, with no ill effects. Yet. No matter if all the options are disabled. Learned that when the capacitors near the socket were stopping my waterblock from touching the CPU, couldnt figure out why it kept powering down after 8 seconds, hehe, until I jumped into the bios fast like and seen the temps! 116 c? Wow, now thats a TCase!