My license expired on my birthday. i renewed it at the dmv and they gave me a temporary credential paper. is this sufficient (with my expired license) to rent a car?

Yes just be sure to update your profile with the new expiration date. Assuming you are a Hertz member

Check with hertz, a phone call should take care of everything

It should be good, but I would call Hertz to double check.

I believe so. The temporary license has the same information that will be on the permanent and it can be verified