What are your symptoms that makes you think its your hpfp and not and ecu like the dealer says? It's possible that the ecu was damaged during reflash by your apr dealer, it's not common but it happens.
But to answer your question, driving in limp mode is not recommended but it is 'ok' to drive it to limp it to the dealer (or home in your case) but I would not drive it on a daily basis in limp mode.