You included, almost as an afterthought, the possibility of running down the Baja peninsula as well. That is a LONG ride . . . and unlike anything you will encounter in the States. FWIW, it is my favorite touring route, but it is long, and there are several challenging climbs. Going southeast out of Guerrero Negro likely will feel like a 200 mile climb with the headwinds you should encounter in the summer. And, it will be VERY hot.

My suggestion is to save the Baja for another trip . . . it needs three weeks on its own to be done correctly. (I have done the entire ride in just over 10 days, fully supported, and it was BRUTAL!)

Finally, don't pay attention to the naysayers re Tijuana. It has its problems, but there are beautiful sights to see and, as always, incredibly friendly people. Just don't be out and about at night, and definitely avoid the east side.