stutech
6
You can copy/paste patterns between projects. I think the songs will not work unless you have the same patterns copied to the same slots in the target project, you might need to rebuild the songs if the pattern slots change.
As for tempos, I’m afraid you can only have one global tempo value per project. You need to manually change the tempo if you need certain patterns to play at different BPMs. If you hold function while changing the tempo, it will only change to the new tempo value once you let go of the function key, that can make tempo changes more snappy.
If you don’t mind a unified tempo, uou could use warping in live for rendering the bunces at one global BPM value. That might make things easier on the AR end of things.