I was gonna do a quick reply because I love to chop those classic rock samples, but I ended up with a full guide. It's long, but it's not hard. The key is preparing the sample before it ever ends up on your pads. Do it right from the beginning and you'll never have a problem, but neglect it and you'll end up with problems you just can't fix after the fact.
1. Pitching up or down, I actually have no idea. I don't do a lot of pitching anyway.
2. Get dirty chops, maybe making your own attack by starting after it then adjusting. Cut the end off so even if you hear reverb over your sample you don't pick up *just* the reverb. Then add your own reverb to all your chops of the same instrument until the space sounds right.
3. I use Ableton, so this is my process. It's a few steps, but it doesn't take much thought and you'll be left with a perfect sample to chop and use.
Step 1 - Before chopping, warp the phrase to the tempo you want to end up in using Complex Pro with the highest number of grains you can. Then place a warp marker at the attack of every single note you can find (don't use the ones Ableton suggests). Now you can quantize it. You should be able to tell if you need 8th, 16th, 32nd precision or whatever. If it's too off just manually correct the warp markers. You should be left with a sample that has no swing. It might sound weird being too straight, but that's what you want.
Step 2 - This relates to #7. The reason pitching down in a sampler ****s up your attacks is because it's actually stretching the sample out. If you want to pitch your sample, do it here instead of in the sampler because it will use grains to pitch instead of slowing it. You might find your attacks are ****ed up just from warping the sample. What you can do is add a new warp marker at the beginning of the attack and one right at the end. Drag the second one slowly towards the first one until it sounds natural. You can do the same thing with your release. I also like to add one in empty space before where the next note is so I can change the length of that whole chop while still having total control over the attack and release.
Step 3 - Freeze that track and drag your clip to another track. That will give you a new warped wav sample. This is important because when you slice it, the chops go back to how they were in the original sample (mistake on Ableton's part IMO).
Step 4 - Put warp markers where you want your chops (again, they'll be gone since this is what the raw sample is) and slice to a drum rack.
ALTERNATIVE METHOD: When I have a really hard sample, I drag it onto the arrangement view, warp it to the right time (but not nitpicking over individual notes. Then in the arrangement view, I click where each chop would be and CTRL+E to break it up. I highlight all them, cut and paste into the SESSION VIEW on a new track. Still having them all highlighted, go to the launch mode and change them all to not loop, launch mode either trigger or gate, no quantization. If you click on any of those clips in the track, it will play it as a chop. You basically get the effect of them all being in an MPC in the same choke group.
Now what I do is I go into midi map mode, click on each clip and map it to a button on the MPC. I do this so I can play it from a pad while editing it with warp markers. You get a level of control you just can't get from the Ableton drum rack/sampler. When they all sound right, freeze that whole track and drag all the clips onto a new track to render them as WAVs. You have to do this because, again, the sampler will just pick up whatever is in the wav. Make a drum rack and drag them all onto the pads and you're set. This has you set up with perfect chops.
With either of these I also usually draw volume envelopes just to perfect attack and delay rather than relying on the sampler. Again, just an issue of having more control.
3) Just said how to get rid of that swing.
4) The problem of decays can be fixed warping as I described above.
6) Using the second method above is the easiest way to get rid of those flams without ****ing everything else up. You can fine tune the start point and attack to get rid of the flam, then warp anything else that might **** up your swing.
Last thing: This process gets you as close as possible to being able to control the swing 100% just by how you play or using MPC swing or something like that. Sometimes though there are little things that **** up your swing just slightly and it makes the whole thing sound off. If you render your sample as you played it, you can fix most of these by just warping that rendered phrase.
