Brother in-laws son living in one's house

Q: Please send a dua or waazifa to read. My brother in-laws son wants to come stay with us and I don't think it is right when I have a young girl of 13 years in the house and he is 17 years old. I also feel that I will have no privacy as I am full time in scarf. My husband and in-laws feel I am selfish. I don't want to hurt anyone but Islamically I don't think it is right he is not my son. Please help to read something that he can understand and agree to stay somewhere else or travel daily to his parents than staying in my house.

Performing Salaah in the forbidden time

Q: As I live in a city and because of the buildings, I can't always see the sky openly. How can I determine that time when salah is forbidden? Is there any trustful program to use, do you know one? I hope it is the one that shows time as salah calendar as I don’t always have wifi on at home? And also, if I didn’t make my fard yet and the forbidden time started, can I still make my salah if I see that due to some reasons I will miss it - like toilet is busy, water is going to be off, etc? How sinful is it to make salah at this time? Also, if I start salah some minutes prior to this time and ended it when this time has started, do I have to repeat my salah?

Bad behaviour

Q: I have a 3 year old son that gets very angry at times when he is scolded or reprimanded for doing something wrong. With the result he tends to get a bit aggressive with people around him. Is there a duaa I can read for him?

Halaal and haraam meat

Q: I would like to know about meat or chicken for selling in non-muslim shops cooked or uncooked. Are Muslims allowed to buy that meat or chicken?  Can Muslims go to Mcdonalds in non-muslim countries? I heard that chicken can be halaal for Muslims living in western countries to eat in Mcdonalds and to buy in non muslim shops because chicken don't have a lot of blood compared to other animals. Is this true? How can I know which meat is halaal and which haraam while living in a western country? I am really confused about this matter and it makes it hard for me to chose the right food. Can you please explain this to me?