RE: your point #1, we've started using letterfeed.com which works with your existing Google docs and provides really great diffs.
RE: your second point #1: Box is doing exactly what you suggested. they hired the creator of Google doc (Sam Schillace)
and created a lightweight box document editor.
RE: your second point #1: Box is doing exactly what you suggested. they hired the creator of Google doc (Sam Schillace) and created a lightweight box document editor.