There is certainly plenty to do and see in the Southwest and your big decision is whether to spend more time here or in Hawaii, only you can decide.
As Michael said. it's doable but a bit rushed for a ten day trip taking the routing into consideration. You could drop Lake Tahoe or San Diego from your plans to make it a more relaxed trip. Choosing between Death valley and Kings canyon would also free up a lot of quality time elsewhere as opposed to trying to see both.
With 10 days another option would be to consider swapping Kings canyon for the Grand canyon, San Diego for Vegas and leave out Tahoe. That would take shape something like LA > [maybe Mojave/ Joshua tree] Grand canyon > Vegas > Death valley > Yosemite > San Francisco > LA via PCH.
With 16 days it opens the door to more possibility's. Have a look at the links Michael gave you have a think and when you get an idea of what your options are and how long you have let us know and we can help piece your trip together with you.