I've gotten the feeling that I've inputted some sentences into my SRS that aren't in the Tokyo dialect. That isn't itself a bad thing but I'd like to know if a sentence would be more commonly heard in Sapporo for example. I was wondering, are there any rules or things I should look out for that might indicate that a Japanese sentence is non-standard?

The only way to know is to know standard Japanese well enough to recognize something not part of it. There is no way a rule can describe when something is a dialect since standard Japanese itself is just the Tokyo dialect.

Pretty much what Jarvik said. Could you provide rules for recognizing non-standard English? Probably not. The most reliable way to recognize dialects is to familiarize yourself with the ones you may encounter.

If in doubt, you can post any dubious sentences here, and one of us can probably help you out.

Cheers lads, but I'll probably refrain from polluting the board for my own gain.