It really depends on your relationship with your parents. In our house our kids always brought everybody home right away. Is there something about your relationship that you would not like your parents to know? Is your father and/or mother overprotective to the point it embarrasses you? Also, in some cultures introducing someone to your parents is a giant step in being a very serious relationship. All of these have to be factored in to making your decision as to when to have him meet them. The fewer secrets there are, the healthier the family.
Since she didn't know, the real key will be her behavior. If her behavior remains the same, stay with her. If not, the money has made a difference in her feelings.
It's NEVER impossible, but it is hard. Seek professional help from someone who has experience in these type of situations. I've had several similar cases, so I know how hard it is on both people when others are tugging on them.
Things can always be worked out if that is the true goal of both parties. That being said, it requires an extraordinary amount of work and commitment.
There is no one right answer. It was a gift, so most people understand that. There have been many court battles over this. Generally, it's still considered a simple gift and not an arrangement.
Explain your reasons honestly. Just because she drinks more than YOU think, does not make it a fact. It may be that you can't be with someone who drinks more than you should. You'll have to see what unfolds.
It's not that he didn't trust you, it's that he wanted to factually trust you. You should do the same. In this day and age, it never hurts to have as much information as possible in relationships.
Unfortunately, the world has become so polarized, you can no longer make certain comments, even if the intent was innocent. Your comment could, with certain people, be thought of as a gender-related microaggression.
WTF? Is he living in the 1950's? You need to start setting boundaries. Let him do his own laundry, make his own meals, etc. Basically, go on strike with EVERYTHING.
If she can't do it herself, do it together. Don't do it alone. You won't get anywhere.
It doesn't make any difference whether or not you like her. You should not have to pay for his gift. He's old enough to take responsibility but evidently not mature enough. This should be a lesson for him.