Raj, interesting questions there. My take is whether a processing mimics a wet room technique or not the end result should touch our heart. I think achieving the look at feel similar to wet room processing is a different goal compared to trying to getting an output which shapes a feeling. If the process leads to it so be it! I think the most of effect what we see in Nik's SilverFX can only be felt with prints.
About this image, personally I don't prefer circular vignetting much (I think the best test is to look at a small thumbnail). I would lose a bit of definition/resolution on the tree to go with the 'age' the grains/tones bring in.
BTW, after seeing the video which Madhav posted I know the origin of those torn borders in SilverFX. It again comes from wet room!!
BTW, I found [url=http://www.ppmag.com/web-exclusives/2007/07/making-digital-negatives.html]this article on creating digital negatives interesting.