WBF - Nice stuff bro. I guessed 4.5, just based on your service (easily 100+), and his ability to contact it most of the time, plus he hit a few groundies that looked higher level.
After watching HIS service games, yeah, 4.5+++. He has power, spin control, and very good placement.
As far as how he was running you all over, you may be able to adjust that a bit. I noticed after his serve, he usually(usually *wink*), hits the next ground stroke right up the center. Then you usually hit it back almost up the middle. THis is where his third shot goes into a corner, and puts you on the immediate defense, while he stays in the middle dictating from there on.
I think after you hit your service return, pay special attention to your next shot, and try to place it deep in one of the corners safely, so he starts off moving himself, while YOU, are now setting up in the middle. Your dad places the ball so well, you have to get him off his base right off the bat, and don't allow him to set up so well. Try it, and see if that pays some dividends and keeps you in the points longer. Obviously, he is good enough, that any neutral ball you send him, is going to get placed so you are on the move defending.
Great vid - this one was really fun to watch.