If OP can be claimed as a tax dependent on a parent tax return but a parent does not make the dependent claim, OP is not eligible for a stimulus payment, even if OP files his/her own tax return.
https://www.irs.gov/coronavirus/economic-impact-payment-information-center
Also:
- Taking the above action would not in and of itself make OP independent for FAFSA purposes.
- The parent(s) would lose the $500 qualifying dependent tax credit that they might otherwise qualify for.
- The parent(s) would not be eligible to claim an education tax credit for OP (American Opportunity Credit or Lifetime Learning Credit), although the OP might be able to claim at least the refundable portion of the AOTC on his/her own return.
In summation, it’s probably a very bad idea (financially) for OP to file his/her own tax return if OP has no tax liability. Oh, and the bright side is filing your own tax return probably won’t affect your need-based financial aid.