Dougness, you have a lot to think about and kid yourself NOT - "things will not sort out by themselves" - unless you take charge. While I find it impossible for us to correctly evaluate your situation (as we don't know you nor your wife's family), I still would like to point out a few things for you to consider:
Long-distance relationships don't work with Thai girls
You are either there right next to her or you are not (accounted for). This is a sad truth. I myself learned this the hard way. While my relationship with my ex-girlfriend was from the dream category when we were together, she ended it abruptly and mercilessly when I had to depart (from Australia) for Europe. The swiftness of this ending was very hurtful and the speed at which she managed to replace me was ridiculously fast. I will never forget the phonecall I made to her upon my arrival back in Europe, when she told me - and I quote: "I have a new boyfriend. It was great between us while you were here, but it's over now. You are not here but he is." ??? In 2 f.....g days? My "tilac"? I didn't cope well with this. I didn't understand how she could dismiss everything that was there between us so quickly. Her new boyfriend promissed to marry her and take her to the USA. In order to go through with the marriage and the immigration procedure, she had to go back to Udon Thani (or so was she convinced). But things didn't work out so well for her. Her new boyfriend didn't like the amount of the sinsot her family was expecting to receive and the US embassy didn't like the whole deal. The boyfriend made his exit, she got stuck in Udon. What do you think was the first thing she did? Yes, she called me up. She couldn't understand my outrage when she proposed we get back together. To her - then was then and now is now. For a long period of time I believed that this was just her bad attitude (that I failed to notice while we were together) and that I was completely mistaken about her. It took me a while (and lots of counseling from those far more knowledgeable on the subject) to get to understand that in her own mind she didn't do anything that could be considered as inappropriate or morally faulty. Back to the point. You either relocate to Thailand or you take her out of there and have her stay with you in your farangland. These girls are not cut for long distance relationships.
* Note to other readers: If you spot a girl with an exceptionally good English working at the reception of one of the larger hotels in Udon, just let her be. She's a heartbreaker!
Too much of financial support backfires
You correctly stated that many Thai people have no understanding about the notion of our "income versus cost" reality. You set her expectations too high straight from the beginning. The amount of money you send her is just too ridiculous and does you no good. You should be sending her only so much money that she needs in order to make a comfortable existence in her environment. They (her family) must think now that you are their "easy way out" for their problems and the likelihood is that they will try to "milk" you as much as possible. You are not gaining any respect or face value this way. On the opposite. Tell your girlfriend that your financial situation is temporarily stressed and that you have to reduce the level of support you've been providing to her. Try to find out what is the "comfortable life" minimum and don't pay her anything over that amount. As Aardvark suggested, then you will see how much of the substance in your relationship is money-based and how much of it is her genuine affection towards you.
You can never beat the weight of her family unless you integrate yourself in it (and dominate it) or take them out of the equation
The most successful Thai/farang relationships I am personaly aware of are those when the farang managed to become an integral part of the (Thai) family and made it to the top on the social ladder. This is incredibly difficult to achieve as it requires a thorough understanding of the Thai culture and the way they think - and more importantly the exercise of it. I personally couldn't do it as I have many issues with their way of thinking. But if you settle in Thailand and make it your home, it might be worth the attempt.
The second successful "beat the family influence" strategy is to separate your wife and her family by taking her as far away from them as possible. However, this alone isn't sufficient. If you bring your wife to your farangland and then she spends most of her time with you in isolation, it will only make her miss her family even more. You need to integrate her and make her feel comfortable not only within your family but your social circle as well. That's not an easy task and it will certainly require an ocean of patience, encouragment and effort on your part. But once you have achieved this, then you have won. Once they get used to the western life style and the environment (and comfortable with their position within it), they will gradually change their opinions about many things (including their relliance on her family back in Thailand). But again, too much of everything isn't good, so make sure she doesn't become too independent of you while getting familiar with the new environment. She may then choose to excerise her new independence and you might never hear about her again.
But again, both ways require you to actually live with your wife.
Investigate outside the family, don't go for confrontation
Confronting her (or her family) and trying to figure out "what's going on" this way is unlikely to produce anything positive. If she has been using you, pulling your money out and stashing them away for her own good, then she will make her best effort to conceal this. Even if she is "innocent" on this charge, she may still use lying to avoid conflict with you.
I would most definitely hire some PI agency prior to your next journey to Thailand (you can do it over the web) and have them investigate a) whether the debt obligation (which is now supposedly being solved with your money) ia a genuine issue, b) thorough background check on your wife. Only then I would confront her and even then I wouldn't let her know about what you found through the agency.
Any decision or conclusion you will make, it should be done while you are away from your wife. I just find their presence too stupifying and myself unable to think rationally when they start whispering in the sweetest of the sweet voices or when they put on the crying show.
I think I've exhausted my opinion on this issue. Good luck in whatever you decide to do and do keep us informed!
