You cannot change who is your mother.
If your father remarries then his new wife is automatically your step mother, when you marry your spouses mother becomes your mother-in-law.
You can change who is your next of kin when you reach majority.
Probably not. The fact that you are a minor with a child does not change that you are a minor and your parents are legally responsible for you.
Yes
You can petition the court (the one which has previously ruled on the issue of your parents' divorce). You should state some important reason why you are better off with your step mom rather than your birth mom, not just that you like her better.
Legally, No!
Legally? To my knowledge, heck no, but in this world, you can expect anything.
Not until you legally turn 18.
In this jurisdiction, an 18-year-old can legally strip.
no, not until legally 16 or 17.
Not legally.
In most places, a 25-year-old dating a 17-year-old is not legally allowed due to age of consent laws.
Apply to the court for a change.
No, in most places, a 16-year-old cannot legally marry an 18-year-old without parental consent or a court order.