I have selfish motives in trying to help a friend!

[Cadet]

Please advise if I am overstepping my bounds.

I don't think so.
Giving him DB information is a good thing.

I am hoping that if he can work on his marriage and make positive steps forward, that might help my marriage, and vise versa.

I dont think what happens in his marriage will matter in your or vice versa.
I would lower that EXPECTATION.