All in all you have a very good plan and at a relaxed pace. Hopefully the Tioga pass will be open, but as mentioned previously, there are no guarantees. You could still head to Yosemite the same day by going around the Southern end of the Sierra's but you might want to leave your lodging options open as you could continue to the Lake Isabella area if you had to head South and make next day's drive a little less. You would have time to fit a visit in to Monument valley between GC and Page if you wanted to. For Bryce canyon, you could check out 'Ruby's Inn' right by the park entrance. It'll cost a bit more than in Tropic I expect but it's a pretty cool place.
LA to GC is quite a long day on the road, although perfectly doable if you are OK with that. If not you could stop on route at Kingman or Williams for example and finish the journey next morning.
I don't know about beach's but Monterey and the Cambria area's are both popular towns for stopping in on your way down the coast. You could always book a 'Hearst castle' tour that is located near to San Simeon.