Hey there,
Congrats on the admission. You'll probably have to talk to the school itself about the official degree certificate thing. I'm pretty sure that for domestic applicants they don't need an official diploma, but rather a final transcript that is marked as graduated. I don't know how they handle international degrees...
As for financial support, I got my financial support offer almost 2 months after getting my admissions notice. So don't give up hope!
Hope that helps!