Google SERP Filter Penalty - Per Keyword, Page or Domain?

This is not a Penguin question and has nothing to do with Penguin. So please save the Penguin opinions and advice.

I have a site that got hit by a SERP filter. Building too many links with not enough anchor text diversity, possibly keyword density too. Yah, I know dumb but I was experimenting with some stuff. This was over a month ago so no it isn't Penguin.

The site is only 3 months old so no real loss tearing it down and starting over. But the content is quite good so I'd like to reuse it. Spent a couple days writing and researching.

Keywords:

The site was doing really well for it's keywords but they all started with

keyword1 + other terms

So since I'm hit for keyword1 the site is totally ****ed. It still gets 30-40 uniques a day but all the conversions were from Google traffic of which I now get 0. Pages and site is still indexed. I rank for a few really random longtails that don't have keyword1 in it but that is about it.

From what I've read the filter will remain for 3-4 months and be lifted if I've fixed the problems. I really don't know for certain what the problems are so that seems like a big gamble.

So now to my question:

Is the filter page, domain or keyword specific?

Anyone had similar issue with a site and tried removing all the internal pages and creating new ones with different urls. Not 301 or redirect just same content on brand new pages and had that work. - As in: is the filter page specific? In this case my homepage would still be ****ed but I could maybe recover some longtail.

If the filter is keyword specific there is probably nothing I can do.

So my other option is to build a new site with a new domain and not redirect, just start over. The site ranked in 2 weeks so again it would probably be better to start over instead of waiting out the filter.

I'd really like to hear from someone who's ridden out a filter penalty if you're out there.