Hi Jeffrey!
Here are the answers to your questions.
1. If after turning on VelXF with "~C28,127" dynamics disappear, this means that the command has worked. Maybe you have forgotten to assign CC11 to the fader.
2. Yes, CC11.
3. Hairpins for single notes (and single rolls) will not work.
4. CC11
5. To see the MIDI commands, you have to show hidden objects.
6. How to trigger various cymbal articulations of the VI Percussion library is explained here:
https://www.vsl.info/en/tutorials/guides/sibelius-integration/percussion#cymbals
Pre-recorded crescendo rolls are hard to integrate in notation software, because they never have the correct length. Anyway, you can try a different approach of triggering percussion articulations. It is explained at the following link:
https://www.vsl.info/en/tutorials/guides/sibelius-integration/percussion#general-optimization-tips
Working with dynamic percussion rolls in Sibelius is easier with our Synchron Percussion libraries.
Best regards,
Andi