This is simpler than you're making it. Enter the 1098-T and nothing else. Your income is the box 5 amount minus the box 1 amount; $28,314 - 12,813 = $15,501*. The good news is: it's reported as scholarship income**(line 1 of form 1040 with SCH notation) and not subject to FICA tax, as wages would have been.
None of it is reported as employer assistance and none is eligible for $5250 tax free.
*The previous comment about "normally included on a W-2"is irrelevant. The school put it in box 5 and that's all that matters
**The distinction between "scholarship income" and "other income" is only important, if you can be claimed as a dependent, by someone else. It affects the standard deduction calculation.
