If GW, and especially Temple are reaches for you, then AU is a reach even if you’re applying ED. Temple is a safety school for AU applicants. You also should not be applying ED anywhere that you can’t afford 100% of the costs too, since it’s a binding agreement with little wiggle room. If you can’t afford to even visit the school, you should probablly have a realistic talk with your parents about whether they/you can afford to go. No university is worth a lifetime of debt.
To express interest, you can always email the admissions team at AU to get connected with a current student, since that’s part of how they track demonstrated interest. In responding to another suggestion above, contacting anyone outside of admissions (i.e. professors) won’t help your chances, they don’t track that.