The thing about templates like {{stub}}, {{NPOV}} and so on is that they are temporary by their nature - they indicate a problem that needs fixing. The problem is fixed and the tag goes away.
Agreed.
Project tags on an article would be permanent by nature. That's not so good IMO.
Ah... I wouldn't be too happy with permanent project tags either. I was thinking of projects like "collaboration of the week" which is also quite temporary.
Most of the templates under vote are temporary. I agree that things like {{Template:Album}} and {{Template:DrugsNotice}} might be a bit too distracting to have in the article space. I'd probably support a small unobtrusive link.
I've always felt that the featured label belongs in the article namespace. A small star accompanied with the words "Featured article", linking to more information, would be enough.
Regards, Haukur