Can you open carry an unloaded firearm in every city and county in California?
-If not, what major areas (cities/counties) can you NOT open carry in?
I am not aware of any jurisdiction that has established a ordinance that has prohibited this form of possession and transportation. I believe that state law would preempt such an ordinance.
If you're carrying an unloaded firearm, can you carry ammunition for it in a magazine as long as the magazine is visible, correct?
Yes. As long as the magazine is visable and not attached to the firearm.
Are there restrictions or limitations on this?
Yes. Magazines are limited to a maximum of ten rounds. Importation of standard capacity magazines is prohibited.
How do you refer to the "unloaded check" that LEO's perform?
It is generally refered to as a 12031 (12-OH-31) check or as an (e) check
If you have a concealed permit, does that change how you can open carry?
No. Recent changes to the wording in existing penal code has removed the exemptions that licensees could use to loaded open carry under a 12050 license. Effectively, the license to carry concealed does nothing for exposed carry.
How does an open carry permit benefit you?
Find someone in California that was issued a license to carry loaded and exposed, and they might be able to tell you. Hypothectically, if one were issued the licensee would be able to carry everywhere any 12050 license holder could.
Where can you not carry at all? Here's what I have so far:
Post office, national parks, State parks, and "Sterile areas".
You will need to add to that list any public building (PC171b). And within a 1000 ft of a school (PC626.9).