I just remember to ask about Eligible Federal Loans. Is this true for the unsubsidized Stafford loan?
Yes, Unsubsidized Federal Stafford Loans are eligible for the Graduated Repayment Plan
I would like to ask, how can I request a payment plan based on income? Also, what if I have income that is tax-free or if I simply have no income at all?
You would have to mark it the online application or paper application and you are not required to supply further documentation.