بسم الله الرحمن الرحيم
(1) If the husband and wife do it for enjoyment then as per some scholars of Fiqh ghusl becomes wajib. Hence it is better to do ghusl in this case. If your sexual desire arose when the doctor inserted finger into your vagina then the ruling is the same; otherwise you need not do ghusl as precaution as well.
(2) If that person allows you to live in that house free of cost after taking the money then it is not lawful for you to live in this house as the status of the amount is like a loan and it is haram for creditor to get benefit after giving loan.
(3) It is not necessary, it is mustahab. It is also mustahab to give gold or silver in charity equal to the weight of the hair.
(4) It is also better to give him ghusl like a grownup is given.
(5) It is not correct.
(6) Yes, music is haram in Islam.
Allah knows Best!
Darul Uloom Deoband