OP,
You sound like such a kind measured woman but kindly meant, be very careful.
You loved a phantom.
You do NOT know this man.
He is hugely damaged and dangerous.
He is liar.
He is a thief.
He is an arch manipulator of your daughter, you and his parents.
NOTHING from his mouth should be believed.
His is an angry abusive man.
Leaving her somewhere so that she was scared is not normal, it is abusive.
Completely separate to his gambling.
You need to put aside your love for this ghost and start focusing on the lying toad your daughter married.
He'd love kids.
Selfish twat.
Of course he would.
Tie your daughter to him and leave her in periodic poverty.
OP, I would also start thinking about the future YOU want.
The next 30 years are going to be miserable for you if she is with him.
You need to pick a side and make it clear to her how wrong he has been in his treatment of her.
That he isn't a man that can be EVER trusted.
That to bring children into a marriage with a lying thieving abusive man would be the height of stupidity.
She needs to go to GA for families to hear the full truth of what life is like with a gambler.
She is beyond lucky that she has found out now.
That he would involve her in fraud tells you EXACTLY the type of character he is.
He would knowingly drag her down with him.
If she wants a really hard, miserable life, looking over her shoulder, afraid of the post, her phone ringing, the knock on the door from people chasing money, you tell her go right ahead and have further dealings with him.
As for him doing some sessions and he'll be ok after a few months?
Preposterous.
Recovery involves hard work for years.
Years where the addict is 100% focused on THEIR recovery.
EVERYTHING is about THEIR recovery.
Not someone to be in a relationship at all.
The bottom line is, you need to tell your daughter in clear unambiguous language that having anything further to do with this man will be throwing her life away, and you want her to be clear with her, that that is what she will be doing.
If she refuses to go to the GA families because she doesn't want to know, that is denial.
Support her OP, but don't try and fix this.
She is a married woman, and adult.
Treat her like an adult that needs straight talking to.
Talk to her so that she knows she is making decisions that will influence the rest of her life and she needs to own that.
Her choices will ultimately be on her.
Kind, but tough love is required IMO.