4 day/ 4 park is no problem. You will have a wonderful time and not be able to take everything in at any of them.
Parkhopping, if using the buses at least will eat another hour out of what could be very full days.
There are a lot of things that can be going on that are not immediately obvious in your brief interaction with someone.
My wife is a healthy and fit woman and only 37. She can and does ride road bike 20-40 miles at a time several times a week. However, walking distances and extended standing...
Our family did this quite innocently for the Christmas party. Being totally new to the process, we had tickets but weren't sure where to get the wristbands. We made our way to the front of the park and saw the CMs putting them on. I assumed that they would have scanned our bands before, but...