The National Parks pass is $80, and covers the entry fee for everyone in your car. However, it does not include camping fees or any other extras. You can buy it when you arrive at the gate of your first National Park. If you plan to visit 4-5 or more National Parks, it is a great deal.

Your route looks solid, although its hard to say what you are planning to visit in California at this point. There are lots of choices, and I suspect you'll want to check out at least some of the Coast Highway.

A note about the RV rental, the reason why I keep bringing up the "extra" charges is that $2000 for a month long rental, that's both a one way trip with drivers under age 25 sounds almost too good to be true. For a trip like this I would expect that you will be paying at least $750 for the underage fee, and at least $250 for a one way drop off. $1000 as the base rate for a month long RV rental would be a very good price indeed.