It's called a rebuttable presumption, an argument for an adjustment based on evidence that costs not directly related to the child need to be a consideration in setting the amount. However, this is a two way street and can be used by either parent.
It can be modified, but not stopped.
Not usually, but there are some cases in which you might. 1. Some states require the non-custodial parent to continue to pay child support if the child hasn't graduated high school and is still living with the custodial parent. 2. If the child is disabled, there is no cut off age for ending child support. The non-custodial parent will continue to owe child support for as long as the disabled child lives with the custodial parent.
It seems unlikely that a non-custodial relative would have "standing" to request a change in child support.
until they are 18
Once paternity is established, the non-custodial parent has the right to request visitation, just as the custodial parent has the right to request support.
Yes. Child support is for the "custodial parent". If you are not living at home with your custodial parent, then they are no longer eligible to receive child support. However, the non-custodial parent can request a modification if the child is no longer living with the custodial parent and that includes a change of custody. A 17 yr old is not emancipated in Texas, unless proper procedures through the courts have taken place. If that is the case, then the custodial parent and child are no longer eligible for child support.
Yes.
Yes, if the NCP has little or no income of any kind.
They can't simply "give the child to you." You need to return to the court and have the custody order modified so you'll have legal custody. It will go easier if the current custodial parent consents to the modification. At that time the current support order should be terminated and you can request child support if you wish.
Petitions (lawsuits) can be filed to modify a current child support order either by the custodial parent or the obligated parent.
yes
The custodial parent is the parent with custody/guardianship of the child.