Sample Texttile based markup follows:
== Title == ''Less emphasis'' '''More emphasis''' '''''Ridiculous emphasis''''' * List item A * List item B ** Sub a under B **# num1 under sub a under B
I really don't see anything wrong with your argument about strong and em -- largely because of your alternatives and their semantic meaning. However, other questions are left unanswered by this: a search engine for instance can weigh a strong element closer to that of a keyword, how would that fit in with what your saying? How does the unusual content matter -- and why would you want to markup as special something that is unusual but not important? Are all things unusual supposed to be defined elsewhere as important? And, what makes basis special?
More importantly, you still don't address the simple fact that often the people most capable of documenting, the users, are excluded from the process because of the learning curve of the version control and the commit bit needed. Cleaning up pod is analogous to using a worn bandaid to hold closed a bleeding neck wound. I'm not against pod as an option -- but I think a bigger achievement would be delivering wiki-like functionality into perldoc, and a better default would be wikitext, redcloth, or any variant of Texttile.
I hack for the ladies.