Do I have to add my 1098-T form to my taxes if I only use FAFSA loans for school?

You are not required to enter your 1098-T on your tax return.  However, the 1098-T is used to calculate any education credits or deductions such as the American Opportunity Tax Credit and the Lifetime Learning Credit.  For more information on 1098-Ts, see the link below:

• A Guide to 1098-T

The 1098-T is only an informational document. The numbers on it are not required to be entered onto your tax return. However receipt of a 1098-T frequently means you are either eligible for a tuition credit or possibly your student has taxable scholarship income. 

If you claim the tuition credit, you do need to report that you got one or that you qualify for an exception (the TurboTax interview will handle this)

You claim the tuition credit, or report scholarship income, based on your own financial records, not the 1098-T. 

Tuition paid for with loans IS eligible for the tuition credit.  So, you (or your parents if you are a dependent), most likely WANT to add the 1098-T.  The tuition credit is worth up to $2500.  Tuition paid with scholarship money is treated a little differently, but there's  a way to get the credit even if you are on scholarship.