This is one way to do it, and depending on the details of your game, could very well be the easiest. There is no one size fits all answer to how to solve this problem; there are always trade offs when choosing a solution to a problem, and which one you choose should be entirely based on weighing those trade offs against the problem's requirememts.
Also, for the second question, are you using opengl or the android graphics api?
My blog, Inverted Keystrokes
, is looking for aspiring developers (not necessarily with Android) to post articles. If you have any development experience and are interested in participating, please PM me. =)