a) I have previously had a cache I owned reported as "needs maintenance", but my stats show 0 for that attribute, so it seems that the attribute counts are current attributes.
b) The Hides tab includes all caches you've hidden, so I assume it would.
If you're a paying member of PGC, you can use a custom filter on Map Compare to find your active caches with the attribute. Go to your username in the top-right and select "Custom filters". Create a new filter, adding statement(s) for Basic: Cache Owner = (you) and Attributes: Needs maintenance (add as required). Then do a Map Compare and add this custom filter.