Hey, sorry for my late reply. Thank you again very much for all the info! I am now already in Buckhorn, New Mexico. The Tour went very well so far, the dessert was no problem, besides the fact that I had strong headwinds, started late and didn't make it through it in one day. But it was easy to spend a night in the dessert, only the cojotes scarred the shit out of me. I carried 2 gallons of water with me, but had nearly a complete gallon left after I left the dessert the following day. btw: the cola dispenser at the closed glamis store stole 1,50 dollars from me by attracting me with fresh cola, but it was empty and the coin dispenser didn't give the money back I threw in.
There was one very unpleasant surprise on the tour so far: the campground in San Diego. They wanted 71 Dollars for one night in a tent, 71 dollars! I know the ACA says that they don't guarantee cheap prices for the campgrounds listed on their maps, but hey, that is insane and they should take this campground off the maps. I was lucky: a local cyclist picked me up and brought me to a cheap hostel where I could stay for 28 bucks a night.
Also, the climb to Alpine is not as bad as many seem to say. The climbs after Superior and Safford to Threeway are way steeper and way more dangerous, because there are no shoulders on many parts.
Los Angeles to San Diego was very beautiful, a lot of neighbourhoods on the coast are insanely rich. The route is easy to find. Only the industrial Irving was a bit nasty and chaotic. By the way: the soldiers at camp peddleton didn't let me through because I am no US-citizen. So no foreigners are allowed to drive through the camp. I was pissed off at first but saw then that it is allowed to use the freeway to get on the other side of the military area.