Hi,
In order to show headers and footers, the WmlToHtmlConverter would need to have a layout engine to do pagination. This is not a feature of WmlToHtmlConverter – it is the most requested feature, of course.
I have looked at what it would take to add pagination to WmlToHtmlConverter, and it is a non-trivial project. It is not currently at the top of the list, unfortunately.
I am unfamiliar with BFO compliant HTML.
With regards to merging data, have you looked at the DocumentAssembler module?
http://www.ericwhite.com/blog/blog/documentassembler-developer-center/
Cheers, Eric