I've seen lots of complaints on the BA forum that elites don't get free bag benefits on hbo fares, so I do think you're out of luck there. Also, I've been told by BA and by the ground reps at LHR that you only get Fastrack if you're actually in the premium cabins, so I don't think that will happen either. Priority boarding is about it.
I've taken a fair number of BA flights within Europe in coach-- I've found the food and service more to my liking than on the other carriers I've tried (primarily LH), and have usually been able to snag a bulkhead or exit row at 24 hour OCI.