Yes... the GEDCOM export issue (when exporting not all, but only a few selected person) is a known bug. And there is no fix so far, but the full tree can be exported. I see the FTB and the site is under heavy developmen, suffering from several annoying sickness.
I also figured out a workaround to the editable family tree problem. It seems to me, that if there were only one tree on-line imported from GEDCOM, it is not editable, but if there were more than one, the second one IS editable. (And you should delete the previous one).I managed to solve this issue this way. (And the photo cross-references were lost during the process as described in the help section - have to upload again).
Thanks, I also figured out the GEDCOM method after many frustrating failures and it appears to be working. The export is a real problem as I can't send the export to various individuals so they can work on it. From the date of many of the posts, it seems like this is a widespread issue with a low fix priority