If a font states in it license that you can't edit it: would converting it from OTF to TTF and using it fall under editing? Thanks.

yeah, it's editing, and strictly forbidden.
It's the same thing as if you converted a video game from PS3 to Xbox...

But if it's for your personal use, nobody will know.

If you use a good font converter no-one will see the difference - unless they use a font editor.