I am a Reservist and my cousin graduates this weekend. Is it appropriate to wear my dress blues?

Graduation seems like a fine place to wear it, just make sure everything is correct.

Yes it is. Just wear it right and respect it.

I hope you mean ASUs... but yes, that would be a more than appropriate occasion to wear your uniform. Just make sure that it is put together perfectly because a DS will not care that you aren't a basic trainee if you are jacked up.