I need to be able to apply a label to the current set of page versions. I would use this to set a baseline of the selected pages at a point in time. This would require that the label only be applied to the current version of each page. If a page were to change thereafter, the next version of that page would NOT have the label.

I want to use Confluence for requirements management, but without the ability to baseline requirements, I can't. Labeling is a step in the right direction but I don't see any way to apply a label only to a specific version of a page. This is really a different concept than your labels as implemented. I'm drawing the distinction between "propagating labels" (what you have now) and "non-propagating labels" (specific to a version).

I need to set baselines so that QC tests against the same requirements that development worked from, and so development has a stable set of requirements during each sprint.

Additional related features: Ideally, team members could make comments that are specific to that (old) version of the page as well and I've have the option to promote each comment to the next version on a case by case basis.