[rnnw62]

No, I don't think that's a normal response when he cowers. It
sounds to me like he was not given positive reinforcement when
he was young which now makes him leary of human interaction
until he realizes it's alright. Can he still be trained? I would think
so...Get him involved in some training classes to boost his self
esteem and also work with him daily on the floor where your on
his level to build up his trust in you and his new environment.
In regard to his marking...Is he neutered? If not that may or
may not help at his age. Many people use belly bands when
they have such issues so you may want to check into those.
Good luck with your new guy and remember a lots of love and
patience will go along way in turning things around with him.