"How did I fix these files" you ask?

After importing an epub into Calibre, I opened it in Calibre's epub editor.
On the menu bar, I clicked "View", "Check book" and then "Run check".
This analyzed the epub for errors. 
I got a notice that "You cannot have bare text inside the body tag. The text must be placed inside some other tag, such as p or div."
Going to the File browser inside the editor, I navigated to the styles folder and opened the stylesheet.
I found text info which was causing the stylesheet to be ignored. I deleted all explanatory sections bounded /* and */ (see below)
This allowed the stylesheet to be properly recognized and format the text.

/* Style Sheet for ePub Books */

/* Set margins at 2% (This gives a white border around the book) */

*/ Text indent will make a paragraph indent, like putting a tab at the beginning of each new paragraph
The margin settings get rid of the white space between paragraphs, again so it looks more like a book
The text-align line justifies the margins. If you don't want them justified, change it to left, or remove that line
You don't have to specify a font, but you can */

/* Here we make our headings centered
We've also made the headings the same font as the body text */

------------------------

Next, I decided that I didn't like the line inserts marking scene breaks.
Locating a scene break within an html file, I noted that the line was expressed within html as <hr />.
Then I replaced all instances of <hr /> with <center>* * *</center> within the text files

and then added the following style info to the stylesheet.

center {
   text-align: center;
   margin-top: 0.3em;
   margin-bottom:0.3em;
 }

This centered the * * * scene break marker and added a slight margin above and below it.
Save file and exit the editor