Tenant attempts to call or email you and get permission;2.

I know it's hard to do in California, but lack of communication is the first step towards major problems.In Troy, NY, a policeman told me no one may enter my tenant's apartment, without tenant permission, no matter what the circumstances.

If they both or even one of them had a real job outside of the home - rather than this home based "bakery" of which they didn't have permission to have, that would be different. 

hostile or notorious possession, you have to possess the property against the wishes of the owner, the owner has to know you are possessing the property and the owner can't give you permission as that breask the AP.5. 

We are becoming a society of un checked permissives unfortunately.

Take pictures of EVERYTHING (with her permission)3.

If it bothers the other tenants (even if its just you) or they don't pick up after it, permission is REVOKED to have the dog.

Be sure to check for limitations on assignability; some realtor contracts say that the contract is assignable only with written permission of the seller - you probably don't want that wording, so you'll have to strike it through or have some addendum that overrides.

Having pets does not automatically grant you permission to destroy the property by allowing those pets to pee and poop on the floors.

I also don't allow my tenants to enter the basement without prior permission.