Font Size in 'Comments' box

I recently received a DC/eSign document requiring my signature.  It also had a 'Comments:' text-box in which I could add my comments on the document.  When I typed in this the font size was massive, and I could find no way to reduce it.  I therefore typed: 'Comments sent separately. Font size...', signed and sent the eSign document and sent my comments by way of a Word doc.  When I received the final copy of the document the font size in the Comments text-box had been reduced to a more reasonable size. It would seem, therefore, that the originator of the document was able to change the font size after I had signed the document. So:

1. Is there a way for the recipient of an eSign document to change the font size in a text-box?
2. Is it the case that the author can alter the font size in a text-box in a document that has been signed by its recipient?
3. If so, can he also edit the contents of such a text-box in other ways, i.e. change not only the font size but also edit its contents after a document has been signed?