Well Danny - I do have to disagree with all due respect.
For one - the fact that the rules have been there for years, doesn't make them good or usable.
Just consider the availability of FX for photo manipulation now and just a couple of years ago...
Secondly: Any rule with vague percentage measures that are automatically cause for interpretation is a bad rule. There is no way to really "measure" percentages in a satisfactory way. Period.

I agree with the notion that moving photo art or manipulation might create new problems. Why not create an entirely new Category e.g. Photo Art - and at the same time clean out the general categories?
Have a main category 3D that contains Poser, Vue as subcategories etc. One Photography w/ subcategories, one 2D and one Literature...
That would really clean up the current navigational mess that offers way too many choices as to be intuitive.
And along the way this and issues alike can be taken care off by creating a thought through and balanced navigation and categorization. The current one is a result of the growth of R'osity over the years and had categories wildly added - a consolidation really would be in order.
Renderosity owes that to it's users - even if it means that work has to be done.

Cheers
kjpweb

"Life is not measured by the breaths we take, but by the moments, that take our breath away!"