Welcome! These are all good points - but it’s best if a single feature request addresses a single need, otherwise it becomes a broad discussion with nothing in particular to vote for. I don’t believe there’s a votable topic for point #1 yet, so maybe that can be what we vote for here? Point #2 already has several votable topics open for it:
Search results for ‘curve histogram’ - DxO Forums
Point #3 (color labels/tags) is already in the works for PhotoLab:
[Poll] Color Tags usage in your workflow? - DxO PhotoLab / Which feature do you need? - DxO Forums
I hope this helps. 