We have a lot of "aborted/outdated" project/tool on the forum for card creation...
there use to be a tool for card creation... it's a little bit outdated and the link are broken : viewtopic.php?f=25&t=7
was working fine... I will have a look if I still have a copy somewhere...
Autilo was also working on the Magic Wagic : viewtopic.php?f=25&t=312
it was plan to include a card creator but has not been released yet.
Last but not least the MSE template : viewtopic.php?f=25&t=853
allows you to "export" card code, it's not perfect but it spare a lot of work when creating custom set. The nice thing is it can recognize some basic auto and ability line based on the text of a card.
I'm not sure it would be possible to add something as complex as being able to manage all the workaround on the forum...
For the card creation related to the official set, I'm not sure such tool would be really usefull as each time the game evolved or a new workaround is found then we have pratically all cards added by herr Doktor to the official release... so there is not really a need for such tool... at least for the official release.