The EC, not the secretary, receives the completed ballots. The secretary mails out the BLANK ballots, because the secretary handles most club correspondence and has supplies on hand to do it.
If there is only one person willing to run for a position, they win by acclamation because the alternative is to leave the position vacant. In which case the president has to select and board vote for someone to fill it. And if there's only one person willing, there's only one person to select.
You will get no argument from me on PDF files. I loathe them with every fiber of my being and would eradicate every last one if it were within my power, but other people seem to like them. Getting rid of them would require some evidence that the majority of members prefer something else.
The procedure for requesting an amendment to the constitution is outlined in article 12, which I again cannot cut and paste because it's a PDF, but the jest is you submit it to me, I present it to the board for vote, a majority vote by the board gets it on the ballot, with a majority vote by the membership the change goes into effect January 1 following the election. So with this being an election year, now is the time to present proposed changes.