Adjusting audio levels in separate parts of a track

[Trebor]

Questions:

1. Can I verify the dB of the adjusted audio section somewhere so that I could then replicate it in other (non-conjoined) sections with the envelope tool?
2. Is there another way to set the loudness of the separate audio sections (eg Sections A and C) to the same level?

Sounds like you need an envelope-follower.
Steve’s dynamic-mirror plugin for Audacity can follow or duck.