Thank you for your patience, Charles. It took me a while to get the images so I could read them. Also, this is the second time I have answered. The system rejected the first attempt. I hope this one goes through.
You should use the signs for x-shaped and diamond-shaped note-heads from Table 1(B). Refer to Par. 1.7.
I would use italics as they occur in the lyrics.
To keep the music cohesive, I would use numbered asterisks and footnotes in the music lines for all of the stage directions.
For the straight line upward with "Oops!" and the arched wavy line with "Bba-a-h!" you have a choice: you could invent signs, or you could describe the devices in footnotes. I favor the footnote.
For the measure with two solo parts, I'd use an in-accord in the music and parentheses in the words.