I believe you have 30 days, as in most states. Of course, it doesn't hurt to let them know immediately.
You can change your address with the DMV ;online or in person with a piece of mail with the correct address on it.
You don't notify the Secretary of State of an address change. Contact your DMV and the post office.
15 days
If its paid and beyond reporting age just notify dmv
Ten days
When selling your vehicle.
yes
10 days
California DMV Cheat Sheets can be found at http://www.dmvcheatsheets.com/dmv/ca-california. Best, Josh
If you want to stop paying taxes on that vehicle I would notify them very quickly. It is to your benefit.
Sell or transfer your vehicle.
If you all ready have one you only need to change the address on it. Contact the DMV on how to change your address or go on their website for instructions.