There's a lot here so bear with me as I try to address it:
1) can stepfather claim your son? Yes, if he is filing jointly with the child's mother and it is the mother's right to claim the child (some custody arrangements address who can claim the child(ren) during which years).
2) child support is not considered a taxable source of income.
3) children from previous marriages often feel left out in families -- whether merited or not. I'm sorry your son feels that way because no child should.
4) If you are living nearby you might consider filing for additional custodial time. I have represented plenty of dads who have obtained custody of their children, so I don't know that your generalized assessment of the "system" is accurate, and I am sure that there is hope of you obtaining more custodial time.
THE LAW OFFICE OF STEPHANIE WHITE
Simi Valley, CA
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