Great trip! It is not realistic just based on the miles alone that you would have to drive each day! there is not enough hours in a day for you visit all the parks based on the total days you have available to make the trip, even if you just wanted to just drive through each park and then on to the next one. Your family could not physically tolerate that much traveling especially with small children. It would be a marthron not a pleasurable RV adventure. You need to take in account the weather you will experience each leg of your trip. 115 degree heat in Death Valley alone would make a miserable trip for your kids with few areas to walk, ride bikes etc.
All the national parks you have listed are wonderful RV adventures to make if your plans include sufficient time to visit and enjoy.
Given the limited number of days you have, I would suggest you would head over to 101 and start traveling north along the whole Oregon coast to Astoria and then turn around and travel south along 101 all the way down the Oregon coast then head home to northern Calif. Strongly recommend you make reservations for your whole trip on the Oregon coast. You can always cancel or change your reservations any time, just make sure you check the cancellation policies for each park. I have made this same trip at least a dozen times and enjoy it every time. RV reservations along the Oregon coast especially the State parks during the summer months are diffcult to get, even prior to the Pandemic virus outbreak.
Or, to put it bluntly, trying to visit all the National Parks in one RV trip is unrealistic and would be a nightmare. IMHO.