Thanks everyone for your help. I think I figured out the margins issue. In my CSS, I set the margins to 15 for all <p> tags. That set some space between each new paragraph, making it easier to read. I hope that is OK to do, to set a literal number (instead of a relative variable - like "thin" or "thick") as the margin.
However, I'm still having a couple other problems:
1) My unordered lists are still formatted strangely. The first element in the bulleted list starts with a solid black bullet point, but all the rest of the listed items begin with an open (white) bullet point. (Yet all items are on the same level, no indentation.) The bulleted list looks find in Sigil and iReader, but it displays strangely in Bluefire Reader and ADE. You can see an example of this in my "Instructions" section of the epub file I uploaded above.
2) I have tables that contain linked numbers, allowing the reader to make a selection that leads them to another part of the story/game. My table is a standard <table>/<tr>/<td> format, with 4 rows of 3, and hyperlinked numbers (0-9) within the cells. Again, in Sigil and iReader, this works as expected, but in Bluefire and ADE, the table displays left-justified (instead of centered), and the linked numbers are unclickable. You can see an example of this in my "Twisted Tales" section of the epub file.
Thank you for your help!
Ben