Not being happy to get married in a certain family

Q: I am in such a dilema, I am engaged and before this I did istikhara and got nothing, so I went with what my heart said. I told someone else trusted to do it and they got nothing too. Now that I am engaged my feelings have changed and I don't want to marry this person. Also the way his family live are a joint family which is not allowed in Islam. He is not independent and have asked if we can love alone after getting married and because he is the only son he said after a few years which will only be sleeping separately, the reason being why I want to live alone is not because of his family the main reason is because of his father and grandmother before getting engaged they accepted that i wear english clothes however I will have to adjust with the family who all wear indian clothes, and now they are both saying that I have no choice after getting engaged to wear Indian clothing. My fiance does not mind what I wear as long as it is decent clothing and the body is not exposed however the family are not compromising, i keep thinking as i am going to be living with his family his dad may say to me you are living in my house and have to do what I say. My fiance does support me but only to a certain limit and he has told me that later he will tell me to wear indian because of his family which is unfair. I don't know what to do but at the same time I don't want to think too much or rush into things.

Oath of a minor

Q: My sister took an oath regarding a specific chair "Wallahi I won't sit on the chair". A) Her intention was that she won't sit at that moment.  B) She is 12 years old and is not Baaligh.

1) Is she allowed to sit on the chair now?

2) If she sits on it will she have to pay kaffara?

Not wishing to take one's share of the inheritance

Q: If a person has three wives, can the last wife ask her inheritance be given back to the other two wives as she does not want to be part of the the distribution although she is entitled to it by Islamic law. So the question is can she sign a document to the effect that she does not want her share and is this practise acceptable from an Islamic perspective?

Allowing someone who consumes alcohol to use one's utensils

Q:

1. If someone drinks alcohol and then uses my utensils for drinking water or uses my spoon will my utensils become napaak as his mouth will be impure?

2. If I use a dishwasher to clean impure utensils soiled by alcohol or something impure will the dishwasher be impure? Do I have to wash it?

3. Once an impure glass which was previously containing impure substance is washed can I consider it pure and use it?

4. Washing impurities in the sink makes the sink impure?