Probably not because it's sounding like she takes care of & supports the child, not you.
No, the mother expended the money raising the child, she is entitled to payment. If the mother has passed away, the estate can claim the money.
If he was responsible for over 50% of the cost of the child, he can claim the child as a dependent. That would mean that no one else was entitled to claim the child, including the father and mother.
Only if he's included in the claim.
A step father has no legal obligation to support a step child.
Normally yes, unless there is a legal restriction preventing him from doing it
Is your mother still alive? Find out if your father made a will. Are you an only child? If not, he made have left his half to another child. Get a lawyer.
No because they already claim you
File a claim of child abandonment and for custody. see links below
No. It depends on when the TPR became final. If the child resided with the parent or a parent for the entire tax year then they may still claim said child as a dependent.
If she has the child 51% of the time, yes.. see links below
If you're in the US, yes, assuming they are filing a joint tax return, they can claim the child on their taxes, even if Mom did not work.
She can't. She might be able to persuade a court to do so. The child support would, of course, cease (and in fact the father might be able to then claim child support from the mother).