Re: American looking for some advice,
i'd say Mamaof3 has given the most solid advice yet. you must reinforce to your daughter that you love her and will always be a support to her. do everything you can in this situation to stand by her side- even if she's upset with you and most likely she will be after she hears your concerns, and more so when she finds out you've been investigating him- STAND BY HER.
if indeed this relationship continues to go forward, and i sincerely hope that she realises this man and his lies are just not the right foundation for a happy relationship, she will need you more than ever, even if she might not realise it or be grateful for it right now.
be sure to stay in touch with her if she moves away with him. it just sounds like he's trying to control the things he says to her and controls the people she meets- today its the neighbour, tomorrow will he tell her oh i dont like your friends or stop having your parents call/come around cos i dont like- then what?
have you sat down and had a man to man talk?
i know that no matter the culture, thats a rite that occurs across the world and perhaps its time you sat down with him in a very non-confrontational environment and with a non-confrontational manner and ask him what the deal is. surely that is your right as a father and it might give you more insight into him. the guy is 50- its something he should be able to handle with no problems and certainly shouldn't object to- after all, he's marrying your daughter!
what was your daughter's initial attraction to him? where and how did they meet?
as an aside a medical condition is nothing to be ashamed of and certainly nothing to lie about. i don't know how relevant this might be but about half my family are diabetics and they usually inject themselves in the stomach or thighs and must take insulin before every meal... i don't know if its helpful, but maybe you could find out where he was injecting himself? and how come if shes living with him, she hasn't ever seen any insulin in his fridge or any used needles in his trash.
She'll be moving away once their married and yes I'm well aware that he's trying to distance her from her family and friends, she's already lost most of her friends.
He hasn't had the decency to speak with me about them moving over 1200 miles away from her family. The only talk I'll have with him will be to inform him that he'll be sorry if he hurts her.
She wasn't attracted to him when they first met, a co-worker of hers was seeing one of his friends and set them up.
I know all about diabetes, one of my friends is diabetic. My daughter has never even seen him check his blood sugar, I don't know what he was shooting up but I bet it was not insulin. He doesn't eat on a regular schedule like a diabetic would and he eats whatever he wants other than pork.
Love eh…does strange things to you 
stupid stupid love 
