If your deck has never been serviced, yes you should send it to Paul so it can be tuned.
If you have a full sized deck, I'd recommend using that for rewinding and transfers and keep the D8 for recording only. Cue and rewind cause wear of the transport. You can even buy a home deck with poor heads and use it for packing tapes and rewinding is you must use your D8 for transfers. My D7 has lasted 11 years because I use studio decks for everything other than field recording. So the D7 only sees as many hours as it is in the field.