Blue Skies for voice and Ukulele - Critique please!

I created this primarily to learn to play it. I have created six or so scores using musescore. I am looking to improve what I produce, so please critique the score.
I pieced this together from multiple sources, including some existing musescore works. But primarily, this is intended to be a copy of what is played on this video by David Remiger (Ukester Brown):
https://www.youtube.com/watch?v=W3yHzPMTvLg

I created this on the Beta 2 unstable pre-release. I liked the spacing from an earlier version, but I upgraded to the current beta and the spacing is slightly squished.

If I am doing things in a non-standard way, let me know. I am trying to learn the use of this program.
One area where I fudget things is trying to indicate the chord change on measure 11. How does the reader know to change on beat 4 without notes to tie the chord to? I put in the little '4' to show this. I was worried that position would not be enough.

Give me your thoughts!