Legal Question in Landlord & Tenant Law in California

No, but they can either revoke your loan if they give you a low rate because you are claiming it is owner occupied or they can not give you the loan.

If you are getting a owner occupied rate, they can make in contingent on you occupying the property.

Only if you want the loan at the owner-occupied rate. Lending criteria and interest rates are very different for owner-occupied properties, versus rentals. People are much more likely to have payment problems with rentals, since they depend on tenants to be able to pay the mortgage and a flaky tenant or taking a long time to re-rent when tenants move, can cause cash-flow problems for the owner which can turn into late or non-payment on the loan. People also are much more likely to walk away from a rental that is losing money, than they are to walk away from their family home. So lenders usually want bigger down payments, and more interest for non-owner-occupied properties. Therefore, they can require you to live in your property if you want the benefits of an owner-occupied loan.