Feature request summary:

It would be great that if you are using a user hierarchy, Admins can have additional permissions to delete notes and emails.

Use case:

A manager wanted to delete an email from Sell but was not the sender and could only see the 'read-only'. They cannot delete it for them, they will have to request the sender to delete the mail from Sell themselves.
However, anyone (admin or non-admin) can edit or delete notes made by everyone. This seems strange to me.
The solution to this would be that that admins can delete emails or notes from cards which are not written by them and for non-admins to only be able to do that for their own. Another option, but more complicated, would be to chose permissions specific to notes & emails just like for leads, contacts and deals.

Business impact of limitation:

It would be a great addition to the features.