If you have a little project and it's getting one or two bug reports a week, it's fine to say that you'll create your own test cases. It's completely different for a large open-source project, where many of the reports are from users/developers who are confused and looking for technical support. With a dozen reports a day and an average of 10 minutes to create a test case, analyze, and reply, we're looking at two hours of time!
I totally agree about the "1 person" part, if several people report a problem it lends credibility to the problem. It may not even be a code bug, but may simply involve clarifying the documentation.
True, but you'll just end up closing real bugs as "didn't submit a test case" if you follow a procedure like MySql. And you'll think you have fewer bugs than you really do.
It's much better to leave them as "unconfirmed" or similar, so that other people can find them and add their own details or test cases. (Of course, I do assume that a project with a lot of "unconfirmed" bugs has no one even looking at the bug database, so it's a double-edged sword.)
I totally agree about the "1 person" part, if several people report a problem it lends credibility to the problem. It may not even be a code bug, but may simply involve clarifying the documentation.