As has been said, doing a little research yourself both using this site [which is packed full of ideas and planning tips] and paper maps you will get a better idea of what is available to you and which of those appeal. Once you have a few more stops laid out and we have an idea of how much of your time you might like to spend in the various places you have listed, we can help fill in the blanks. One area I would point you towards is the National parks of Southern Utah and Colorado which will give you a great taste of scenic wonders, mountain towns, scenic drives and the diversity that nature offers. It should also help balance your trip which seems heavily biased towards the City. Even at the start of your journey you could visit one of my favourites in Yosemite NP by first heading north and then across the mountains and through Death valley to Vegas. Maybe first driving the coast to San Fran, it would certainly be an option and one that I would consider over going from NY to Miami.