Editor using wrong font sizing and when deleting it leaves all the tags..

This was a test of the editor I ran and these are my concerns...lite version with text in a snippet edit area

When I edit an area just adding plain text and then selecting that the text be bolded and from the drop down of the font size 18pt.
What I got was a span tag (ok) the bold used <b> (not ok should have been <strong>) and the fonts size was "medium" also not OK.

I then went back to the page and deleted the text using the editor and then looked at the code and it deleted the text characters but left the span tag the b tag and the font tags. Why not delete all the tags associated with the text?

This seems sloppy to leave all that behind.

Is there some way to config this editor to not do that and to use <strong> instead of <b> plus use the write font sizing such as em or % ?