Are questions like the following appropriate?
"I'm using application X, can you tell me how to do Y with app X?"
I think they're appropriate. In fact, I think they're far more relevant to the mission of the site than the mass of
What's the best [X] app? questions.
These are real questions with objective answers that are specific to the Android platform, so yes, please ask them.
I would say yes. Certainly for built-in and Google applications. For more obscure application maybe not, but those are less likely to get answers anyways