Wrong Partition Scheme
 

I mistakenly cloned an intel machine to an external drive with Apple Partition Scheme instead of GUID. It works and is bootable (I don't know why), but wanted to correct it to GUID. One of the partitions has a data folder that I don't have backed up on the intel mac. Is it safe to to drag this folder back to the intel mac desktop before erasing and reformatting the external hd ?

It should be safe as long as you've copied everything off that you want to keep and, obviously, put it back when you're done.