To take a contrary viewpoint, why do these things matter to you? In particular,
Why does the age of his ex matter to you? If you view it as a warning sign of pathology, the only way it will make any difference is if you decide to use this information prejudicially and cut off the relationship before getting to know him further. If you decide to give him the benefit of the doubt, a little patience will eventually reveal whether he has psychopathology that you cannot tolerate. If you decide to wait and see, you should put suspicion aside; suspiciousness on YOUR part is itself a psychopathology that will poison the relationship.
Why does what he does with his ex matter to you? Jealousy is useless. Jealousy practically never gets anyone to love you more. Moreover, love is a gift. If you try to compel him to love you, or force him to choose between you and his ex, what you get can't be considered love. Whether good or bad, it appears that he is still quite involved with his ex, and you will very likely have to live with it if you wish to get further involved with him. If you can't live with that, then quit now.
The common principle underlying both these points is that you can't control other people. You can only control yourself. You can COMMUNICATE with other people, and try to understand where they're comng from, and let yourself be persuaded, or try to persuade them; but you can't CONTROL them.