Congratulations on all the tweaks!
It took me a while to puzzle it out when I first ran across it, but the text just underneath your title:
<SPAN CLASS='P-AUTHOR H-CARD'>MIRIAM AVERY</SPAN> is occurring because you’re using the microformats 2 plugin which tries to inject the p-author h-card portion into your page, but it’s having a conflict with your theme which is escaping the output for that author section. (More details on this known issue here.)
Chances are pretty good that you could deactivate the microformats plugin to fix the cosmetic issue without causing other major issues. Depending on your theme’s native microformats markup, you may likely find that you don’t see or experience any other major issues with any of the other technology. The one issue I’ve seen people come across here is if they’re using Brid.gy to syndicate their content via webmention to Twitter, in which case having stronger markup becomes much more important. Hopefully this will at least help you track down and either fix the issue or figure out the best way around it for your particular needs.
The best long term solution would be to add the proper microformats markup directly into the theme itself.