Keyword density after penguin?

My sites have been hit really hard, but since I've never been one of those who has tens of thousands links, I think in my case I got hit mostly because of too high keyword density, something what google calls "keyword stuffing". I also have bad links probably, but I don't know what to do about that, but changing keyword density is something pretty easy. Problem is, I don't know how much should I change it, what is right keyword density now and if it will even help, just to delete some key phrases on sites that already have been hit? What do you think?
Another question, if my problem is low anchor link variation, should just ordering some quality link building service here with anchor texts like "click here" "here" etc.. help, or is is just waste of money?
Thanks for any help and I hope this discussion will be helpful not only for me.

I believe 1-2% is sufficient for density.

I would have recommended DripFeedLinks or Dripable for diversity but after penguin, no one really knows if you can do diversity with low budget links or if high quality links are needed for everything.

Do some searches on banklink profile.

i prefer 1-2% 2