Overall........Good job !
Your trip as a whole will work out OK, but trying to plan hour by hour rarely works. It's good to have the knowledge of whats there, but you might not get to see it all. That's not a bad thing it's just some places you will want to stay at longer and others for not as long. A good example is day 4 where you plan to drive over 200 miles and see 3 attractions, whereas a trip to Cave of the Winds and a tour that could easily make it lunchtime before you leave for the Falls and then a 65 mile journey to Royal Gorge where you need the best part of a day alone to make the journey and expense worth while. Another example is Desert view drive in GC, there are many viewpoints and you could spend most of the morning working your way to the village area, and then you have much more the other side to see going out to Hermits Rest via Shuttle bus.
You also appear to have mapping program times as a guide that do not allow for fuel and food stops, rest breaks or any delays such as congestion and construction. Build an extra 20% travel time into the equation for a little 'wiggle' room.
Other than that, and as previously mentioned a little rushed between Vegas and Beatty I'd say your good to go, nice job !
Although I prefer entering the south rim via the Watchtower, given your time restrictions I would recommend staying in Tusayan near the south entrance and go straight to the village area, up to Hermits rest and then exit along Desertview drive. Williams would possibly be a cheaper option of going that way but Tusayan is the nearest if you can find affordable lodgings. HANG ON !......... If you are camping during this trip why not stay at Mather campground right by the village in the National park ?