It is not drastic deleting, it is just deleting the model - if you click the [x] button from 'My Models' you get a warning first that you are about to delete the model.
Yeah Ive always gotten the same as in your "My Edit Page". It displays two files because it is only showing you a history of your updates. If you delete the model it will not revert back to the previous file, it will completely remove that model from your shop.
I've uploaded my file some minutes ago and reported that also as major bug. That currently prevents any update of my models since all are in metric data. Woody64