1. your nikah is valid, there is no any provision in Muslim law that marriage should be solemnized in special marriage act.
2. at the time of your nikah, both parties were Muslim.
3. on divorce a Muslim woman requires to spend iddat period, length of that period is depended upon different condition of divorce.
4. in Muslim law till the age of puberty or BULUGH, mother is the guardian of female child.
5. custody of female child is decided by the Muslim personal law.
6. section 2 of The Muslim Personal Law (Shariat) Application Act, 1937 says :- Notwithstanding any custom or usage to the contrary, in all questions (save questions relating to agricultural land) regarding intestate succession, special property of females, including personal property inherited or obtained under contract or gift or any other provision of Personal Law, marriage, dissolution of marriage, including talaq, ila, zihar, lian, khula and mubaraat, maintenance, dower, guardianship, gifts, trusts and trust properties, and wakfs (other than charities and charitable institutions and charitable and religious endowments) the rule of decision in cases where the parties are Muslims shall be the Muslim Personal Law (Shariah)
7. if both the parties to the suit are agree then this issue shall be decided by the court according to shariah law.
8. there no maintenance in muslim law after the expiration of iddat period, but a Muslim woman can approach the court for maintenance under sec 125 crpc and got maintenance after iddat period.
9. you have monetary and accomodation relief in domestic violence act.