From what I have read, there is no specific requirement other than the permanently mounted camper should be set up for living/sleeping in (a basic shell can and has been denied, but not always).
The "permanently mounted" refers to your use not the attachment type. You should not have to remove jacks, etc., because they are required if you need to remove and repair the camper or truck.
Once you change the registration to a passenger car, you cannot haul anything in the bed of your truck that could possibly be identified as "commercial" (e.g., you can haul a suitcase, but not a couple 2x4s) at any time. From what I read, the fine if you get caught is somewhere around $500.
PS. Can we drop the rant and just focus on the question? It's a good question and it will be a shame to turn this into another California bashing thread instead.