Definitely. When I first found out how many of their sounds were samples I was actually a little sad about it, but then I got an MPC and got into sampling and ended up having a huge appreciation for how great they are at finding and using samples to make truly new music. They're incredible.
I believe that the drum sample for It Doesn't Matter comes from The Fatback Band - Wicky Wacky (Jamie 326 Edit). It sounds like they sped it up by, like, 126.5% speed to me
How do they extract just the drum/vocal tracks so that no other instrument/vocal bleeds into the sample?. Are there special recordings where each track is separate?. If so do you need a special kind of license to access these separate tracks?
Usually just a spot in the track when one or the other is isolated. Sometimes they had acapellas alright. Filtering can be used to remove some of the background sounds alright but sometimes leaving that in adds a bit of swing to the rhythm