cosign. this seems related to this other request somewhat:
http://www.mpc-forums.com/viewtopic.php?f=25&t=149732here is what i wrote there earlier about a possible way to set your trims/loops to match tempo / bars / etc..
i can't speak on the audio track related stuff you've posted as i never use them, but i've come up with a simple interface for setting sample/loop length to tempo in the TRIM screen:
1. go to the TRIM screen.
2. put the cursor over the END value and hit the TAP TEMPO button (this will work whether or not you have LOOP turned on or off).
3. the END value will now change to say "1/16". turning the data wheel will change it anywhere from 1/1 to 1/64. as you do this you will see the selected area change in the waveform display below and you can hit the pads to audition the sample like normal and hear the changes.
4. when you have it set how you like it hit TAP TEMPO and the END value changes back to its normal numeric value and you have your new sample length/loop length set.