As long as you selected just ONE school when you signed up for the DAT, every school you apply to will get a copy of your scores along with your AADSAS application. That will suffice. 🙂
I believe so since your DAT scores will be sent directly to AADSAS and then onto your application, so the schools you've applied to will be able to see your scores. I'm not 100% certain so feel free to correct me if I'm wrong.
Your DAT scores will show up on the PDF that AADSAS sends when your application goes out. So in that sense, yes, schools will get a copy. No need to purchase additional reports, though you can if you'd like.
I believe that you only need to select one school for it to upload. However, it is free to select additional schools. I spent the extra minute and selected them all.