Last I heard, you need to save the recordings to another folder, wait the 8 days to pass and prime time recordings are deleted, then you can transfer them to EHD. I am not aware if this has changed since it has been over a year since I had access to a Hopper, if it has someone will correct me.
Yes, you must save the program to MyFolder and then wait whatever period you have set for PTAT retention. To do this you simply click on that program in the PTAT folder and you will get a drop down that allows you to 'Save' or 'Save Series.' Click on one of them and it will save it to MyFolder. Once the program times out in PTAT you will be able to transfer it to your EHD.