Hi Aayush and welcome to the site
Answering your second question, your future children will carry two beta genes. One from you and the other from your future wife. If you have done electrophoresis test and you are sure that you are free from thal therefore your future children will only be carrying the trait (thal minor) as they will have a healthy gene from you and another muted gene from the mother.
As for your first question, I believe that you are the only one who cwn decide. Marriage differs from culture to culture. In some cultures family bonds are very strong even after marriage and if you come from such back ground it will be difficult to hide because this will cause a lot of problems and these problems will hurt her more than you can imagine and you never know how things will proceed
In other open cultures were families are more independent and no influences from parents, the situation will be different. So you are the only person who can weigh the pros and cons.
But personally I believe that you should not hide ( I don't mean that you go and tell everyone on purpose) but what I am concerned about is that when you hide, this gives you and the people around you that you are doing something wrong or you go hide because you are in a weak situation. I think you should defend your point of view, you should defend what your heart has chosen
What is the difference between a thal patient and a diabetic for example?
?? Thal is a condition that if dealt with in a proper way, you live a normal life and we have a lot of. Examples her of people who have careers,families and children and doing everything others do
You can ask any body who opposes you, what if I married a super healthy person and after marriage she had an accident for example, are you going to leave her because she is not healthy anymore.
Just a thought and in any situation I wish you all the luck and don't stop asking
Manal