hi,
im not sure on the second question.
but this worked for me as well
I suppose you could use the MIDI FX plug-in Modifier, pick CC7 Volume as the Input Event option, and keep the Re-Assign parameter off to prevent a channel strip from responding to MIDI volume mistakenly supplied from a keyboard slider. That should prevent the MIDI CC from reaching the channel strip and adjusting the volume by mistake. There's definitely a better method to accomplish this [globally? ], but that's all I can think of for now.