When transferring a product, the new owner will be able to process refunds and cancellations and lookup old payments. They will not receive money for any of the old and still active recurring. That was a contract with the original owner that cannot be modified by us or PayPal. If they want the money they need to work with the customer to get them to rebuy with them.
Rebills will by default only show up in the new owner's account but if the old owners searches for them directly by transaction id they will be able to pull up the details on them.