Im not 100% sure where to start but here is a question... Was he married to your mother? If not i doubt you will be able to transfer ownership of property over unless she had some sort of power of attorney or whomever in his family holds the power of the estate signs its over. Dont make payments on the property if your ultimately not going to keep it (well your mother or whomever gets to keep it).
Not sure if this is a route you want to go but a Gofundme page might help generate money to have him cremated or cover other expenses. Given his history i would venture to say you would get many supporters.
Sorry you lost your dad