goodroi - 7:24 pm on Aug 12, 2011 (gmt 0)
Those are all feasible options with pros & cons. For example if you noindex and/or delete a large amount of pages it may leave your site with too few pages.
From my POV many webmasters inflicted by Panda simply do not know what is quality content or how to produce it in large volumes.
My idea of quality content:
-600 word bare minimum
-Contains synonyms & semantically related word
-Good readability score (not too high or low)
-Often contains images (humans like pictures)
-Uses bold/heading/italics for usability & not SEO
-Contains a clear idea in each paragraph
-When in doubt I think what my high school English teacher would say