Driving with parking brake engaged

Most important isn't the lining if they are wore bad they will make noise, If the drums are warped you will fell it in the pedal.

What I would be concerned about is how hot did the wheel cylinders get . They will not give you any sign of failure if they go out all at once. Change the wheel cylinders and while your at it do the lining and a hardware kit for new springs. resurface or replace drums. This is only advise you have to decide how safe you feel driving it with confidence.