I am sympathetic to deleting notes, but personally I'd much prefer a way to Edit them. That is only available for the first 15 min or so, and where edits are public.

90% of the notes that I wanted to delete were bc of typos or bc I forgot to say something. Somehow my IQ increases right after I press the post button and I spot a bunch of errors that I didn't when proof reading the post... 

 This should be done by issuing a new note which says it is a new revision of the previous one. Clients can then make the link and show the most recent version (as well as potentially the old one or what changed). 

 Yes, that does seem like the way to go. But on the user's side, the workflow should be intuitive and quick