Howdy CC
I can not answer all your questions in detail about two-spotted mites, as I do not know your situation or standard procedure.
However, I offer this information. As in bacteria reproduction: natural selection has poised genes to hopefully allow some offspring to survive a harsher condition (like one particular organic remedy, as you have found out). This is natural. Yes some of the mites and offspring will express an enhanced resistance to any pesticide, natural or artifically manufactured.
Here is my suggestion> Make sure the mites are all dead when you make the switch to caliclean treatment, ensuring no survivors to reproduce. That is the answer in a nutshell. It is good you switch it up, I do that myself with a few organic washes periodocally.
If I understand your last Question...No. Once upon a time some spiders learned to eat plant sugars and chlorophyll for food, instead of other bugs. These little spiders are mites. Mites suck leaf cellular fluids and cytoplasm. If you burn them with pepper spray they die like a human would be if dunked in acid. Once the leaf is coated, for the mites its like sucking on a redhot poker, burning their mouth off. The either burn right away and shrivel, or starve - as you have destroyed their ability to feed.
Plus, a day later its as if you never sprayed a drop, and nothing remains but a few dead mite carcasses, and some unhatched eggs. Your herb is sweet and unmolested.
That's how it works.
Feel free to drop notes from time to time and best of luck with your good garden brother!
Thank you for your inquest and feedback!
Peace be with you
calibuzz