- Should I use the Audio File workspace or the Audio Montage workspace?
The Montage for sure.
- Which marker types (if any) would be best for isolating and naming individual songs/regions within the files?
No markers necessary, but CD markers may come in handy to enter metadata for individual songs. In the montage, you first see your audio file just like above (as one clip), then use the scissor tool to cut the separate songs. Now you have multiple clips, which are just representations of that particular part of the source wav file. By adjusting the sides of the clips, you can change the cuts after the fact. Clips can have their own processing, but also the tracks on which they reside can. You can create another stereo track and drag clips over if you want the same proces done to them by track effects.
- If my goal is to end up with a bunch of individual song files that are normalized for loudness, what's a productive workflow for getting there?
You could apply effects on individual clips, or use the meta normalizer. I'd be careful with cassette recordings though, since they possibly are quite close together already.