If some major assets are not addressed in those papers, you better think twice about oral conversations with him. Run, do not walk, to your lawyer's office and have those major assets adderssed in black and white. They will promise you the moon and stars...bottom line, they are lying through their teeth in the hopes that you will not draw up papers that stipulate who gets what and when. His question about being a jerk and taking the stuff....yes he would...he was projecting on to you so that you would think he was such a kind soul....please do not believe it...you have to take care of yourself and do not rely on anything he says or promises right now.
As for telling family about the situation...that's on him. He's the one running and he sould be the one to address the issues w/his family.
Take care of yourself and leave him swinging in the wind.
Sit quietly, the answers will reveal themselves when you least expect them to. The past is gone, the present is a gift and you need to focus on today, allow the future to reveal itself when it is ready.