You do not need your rock id. When you go to load what ever app you have gotten from Rock Cydia will ask you to link your account to FB or GMAIL and it will ask for email account as well as recognize the LIC for the phone the app was originally installed or last installed on.
I'm having the same issue - cannot link my RockID. I've used the Google account that I paid with (still have the receipts in there!) but the link is not working and I've lost the apps I bought right before the merge.
same issue here want to redownload goc pro after updating phone to 4.1 and jailbreaking, cydia links to my facebook account to verify my rock id but still requesting my id details and password, so i cant download
I just find out there is a way to retrieve your rock account password.
When you navigate in cydia to an app that uses the rock account, you will find something like link you rock Id.
Follow those steps , the rock id is normally your emailaddress.
When you enter an invalid password, an email will be sent to your rock id ( which is your emailaddress, if registered ).