Holy crap, Frank, your timing is awful. For snakes anyway - lizards will be easy.
- is it worth to stay 2 nights near Mohave desert for night cruising and early morning walks near kelso or will there be no activity ?
Morning walks are always a pleasure. So yes, just from that perspective alone, it is worth it. You will see good birds and lizards and bugs. You could see snakes. You will probably be able to go crazy trying to track sidewinders. You may get lucky and see one or more, "cratered up" under a bush or even out in the open. Now, early-AM walks conflict pretty badly with ugly-late road cruising. Me, I'd skip the super-late cruising, and get out in nature. Early! Like, finish up by 9 AM, and get started a half-hour before sunrise. Or more - just substitute early-AM walking for earlier-AM cruising. Start an hour or more before sunrise.
-which of the named places has the best chance of seeing snakes in july ? I will extend my stay at these places.
Coast and mountains. Then high desert. Low desert is worst IMO. You can cruise snakes in the low desert in the hottest seasons, but numbers are usually reduced and man, you gotta stay up LATE! Like don't even start unti after midnight maybe - it's usually still too hot out. Clouds can help though - watch the weather. And also see below, about water.
- is night cruising near zion (orderville) an option in july?
Yeah, just not a great one. How late can you stay up? Ha ha. However there are some canyon-bottom streams around there where even mid-summer is chilly at night. One warning - flash floods can kill you. Kill your whole family. Pay attention to weather forecasts. Ask, specifically, about flash flood danger in that part of the world.
- is flipping in july an option or will it be to hot for any result?
(I will buy a permit)
Coast or mountains maybe. Generally though, forget flipping in July. It's really mostly a spring thing.
- changing my locations to for instance Arizona is unortunatly not an option. I tried but the wife didnt budge.

The locations are set we can adjust the days we stay.
If you've never been, I'd bounce locations every 3 days or so, and try to see the most variety. If you've been here before, honestly, I'd pass on the low, hot desert. Coast and mountains, man, coast and mountains. Maybe some high desert - say 3000-7000 feet elevation.
- is it correct that the only venemous species dangerous to humans in the area of my trip are the rattlesnakes. No corals so far west?
Correct.
- are there snake and reptile tours in the area?
Couldn't tell ya. None I know of.
- any other tips are very welcome
Learn the legal differences of herping here, there, or that other place. States all differ, anything called "park" is usually no-touch, and public land (BLM or National Forest) is your friend. So again, the principal components of "herping law" are 1) which state are you in (some require no permit, some do), and then 2) whose land are you on (usually there is no specific permit sold for this - usually it's "yes you can herp / no you cannot herp")?
Kingsnakes like water, and are tolerant of agriculture. Also, "evaporative cooling works!" Ha ha. My point is, irrigation (or natural water, like a stream or spring) in the low desert brings cooler temps, especially at night. So walking or cruising near water, and beginning at higher elevations and then working down hill as it gets later, will up your odds. E.g., start walking high-desert spring and stream-zone areas about an hour before dark. Natural water is good or even great for most snakes, but most do
not like farming. Kingsnakes -
common getula kingsnakes, not most others - are different in that they seem to like irrigated farming alright. My experience anyway.
Good hunting! Be careful, stay legal, come have a great time.