Oh c'mon! How can you not know that!? Other than a few ignorant and self-absorbed members, I would smack anyone in the face who ISN'T jealous of your overclocking skills! No lie!
Yes, the idea is to remove imperfections so that there is as little gap between the CPU and the Heat sink as possible. That promotes better thermal conduction. You want both surfaces totally and completely flat.
It's also to make sure the bases of the heatsink and CPU are both flat. Like in the case of the TRUE, there are a few degrees gain to be had when lapping it because the base sucks.
When the time comes for me to really crank up my system (when it starts being "old"), I'll lap my e8400 and my Xiggy and let everyone know the results. That'll be a ways down the road though. I might lap the stock intel ones I've got in my parent's and grandparent's computers. Ain't got nothing better to do
YES! Don't ever think you don't need that. There will always be microscopic scratches and ridges. However, you will need less TIM than normal. I think I addressed this above if you would read through the posts...