I wish I had some pendings to check(!), but this sounds like great progress. All needed and helpful improvements. Doubtless, someone will have more ideas for improvement - development is never finished.
I couldn't check, but does this mean it won't allow saving if there is more than one Biography or Sources section? That would be really nice!
And it would be nice to see on every profile save (merged or new) an encouragement to always enter dates and places, even if rough and uncertain (but not made up of course).