It's not just a matter of how advanced a question is; MO is just not the right place for questions of the form "is this argument right?" whether you are a researcher or not. This is a subtle point, since I think questions like "I seem to be proving something false, where am I confused?" which seem similar are much more in the spirit of the site (though I'm not sure there's real consensus about those; I think there haven't been many).
I just want to make sure you don't interpret one closed question as saying you shouldn't post on MathOverflow again. If you have questions which are right for the site, we want to hear them, no matter who you are.
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