Our main concern was that we picked up in SF and dropped off 4 states away in Denver (1800 miles appx) and the number of different quote variations was incredible. We cracked and rang Avis direct who, we were informed had /have a no "drop off charge (googled UK number) they were exceptionally helpful. We booked over the phone and sorted what was necessary, as you say, we took CDW and 3rd party and unlimited milage, due to our travel distance. Fair fuel policy is receive full, return full, bearing in mind fuel gets cheaper the more inland you go SF was dear, so let them fill it up and make sure you put as little in as possible on your return . Like you we didn't bother with satnav, navigation is easy with planning.
When we completed the booking we asked whether there would be anymore unforeseen charges and was told no we asked for this to be put on the documentation that was emailed to us. Talk your needs through with them, we got the impression they wasn't on bonus unlike the airport personnel.
We stayed in SF for a few days and returned to the airport (30min on BART from Powell the most central stop) You will need to catch sky train to car hire centre on alighting the BART at the airport. The collection went smoothly (5min) and it was made clear we had nothing to pay as we was at the drop off in Denver. Unfortunately a week after our return Avis took €44 out of our a/c, (Airport taxes apparently,) after some interesting dialogue we got reimbursed. If you fancy the drive out of the city, rather than the easy motorway access from the air port ther is an Avis office on O'Farrell 5mins from Powell and very close to the best bar I found centrally "Bartlett Hall"
I hope you're prepared for some interesting walks it's hilly. The Muni bus service is very good, research. Have you sorted accommodation?
This post has been edited by clarevoyant.: 26 June 2019 - 05:40 PM