I personally speak to Nissan UK on a monthly basis re warranty and goodwill matters, for warranty you don't have to go to Nissan for services. However this will be required when seeking goodwill from Nissan UK outside of the warranty parameters for defective repairs.
To uphold the manufacturers warranty you have to be able to present evidence that OE parts were used during servicing and serviced by a VAT registered company at the correct intervals.
As for a running in service, you don't really need it but if you want to I'd just do it yourself.