I at first thought this was a good ideaI at first thought this was a good idea (FWIW I still think it is a good idea, just with a little more tweaking), however, after taking a brief look at your improved query (removing accepted answers) I am a little worried about one thing.
I checked the first 6 out, and of those 6 I found 3 that had good answers that just needed upvoting (and they were good questions too). That is a %50 percent chance of pulling a good question out.
If this trend continues, even anywhere near this high, we would be deleting an awful lot of good content and I don't think clearing out more old cruft is worth what we would be deleting.
Therefor I suggest we also remove questions that have an answer. I know that will still still some junk lying around, but I think the amount of good questions it will save us is worth a little more cleanup on our part. I had Braiam modify the query once more to filter out questions that have an answer. It still finds some 18k questions and after going through the top 7 I wouldn't mind losing any of them.
