First of all, you mention about gender and give to examples 'only talked over IRC' and 'sex change'. microformats work on an 80%/20% rule, and these are extremely edge cases.
Secondly the whole 'rating' of films example - I think you've missed the entire reason for hReview. Note the key is in the name... hReview is for reviewing products/items/things, and not defining them within their specific boundaries.
For example, you can't markup the country-specific age-restriction 'rating' with (current) microformats, but you can rate (or score) that movie, say 4/5.
Also, you can rate products out of ten, for example [span class="rating" title="4"]8[/span].
The reason why you can't markup specific information, such as films, is because microformats are generic.