A: At 12 years old, the judge has to listen to (but isn't bound by) a child's preference as to her primary residence. The judge may, but isn't required to, listen to the child's preference about possession schedules.
Her father shouldn't be telling your daughter that he's having to work to pay you. That kind of thing should be kept between the adults.
A: You'll need to file a suit to establish custody orders in whatever State the children have been living in for the last 6 months. If they haven't been living in the new State for 6 months yet, you may still be able to file in the State they moved from. Contact a lawyer to assist you with this, since interstate proceedings really are not do-it-yourself issues.
A: Assuming the Texas suspension is based on the Indiana arrest, you'll need to ask an Indiana attorney. The states have a mutual agreement that, when one suspends a driver's license, the others will reciprocate. So if the suspension is originating from something in Indiana then the problem will have to be addressed there. and the fact that the charge was dismissed might not be determinative. for instance, in Texas if you were arrested for DWI and the charge was later dismissed, your license would still be suspended by DPS if you refused to take the breath test when you were pulled over.