Legal Question in Real Estate Law in California

Yes, you have legal rights......and exactly what they are and how you can enforce them depends upon what your agreement says about remedies for breach. Typically, you can provide insurance yourself and bill or recollect the premiums from the buyer, but this remedy requires that the contract so provides. I'd take the contract to your insurance agent for his/her advice.

I'd have to read the note and deed of trust that secured the financing. You may or may not have the right to foreclose, or to cover the insurance now and get reimbursed.