Relax. First of all, have you tried to move your saves add-ons folder from your original Blockland directory to the new one? Blockland's main directory is now in the "My Documents" folder.
The latest update does prevent default files from being properly edited, but UI edits and other texture changes can probably wait until someone comes up for a better way to manage them without any overwriting.
So I can just delete all the ones in my current folder and copy the old ones? Also, sorry for sayying I was going to stop playing, I could NEVER stop BL.
No need to delete, just overwrite the ones in the My Documents folder with the ones in your other Blockland directory.