Are you worried you do so much SEO you could have a over optimization penalty from Google, MSN, or Yahoo?
I just watched a video of Matt Cutts giving a brief answer to the question “Is over optimization bad for a website”.
He answered the question very straight forward. Google does not penalize for doing a lot of SEO to your site. so you should not worry about a Google over optimization penalty. You will not get in trouble for using a lot of “no-follow” links. What you need to watch out for is your content. when your keyword density is to high it will start to sound strange do to the repeating of words over and over again.
Some expert however think if you have too much SEO in your pages you will see mixed results. Some tests have been done with images and how they were indexed based on <img> tag attributes. the test revealed if you are using both ALT and Title attributes you received a penalty. However if you just use ALT your image will rank higher, if you just use Title it is worse then using both ALT and Title together. This test was very recent if I can find it again I will post a link here.
From my perspective this is something I have preached since I started on the web. What is the point of a site if it is not targeting its audience, being clear and concise. Your target audience should not be Googlebot. your target is, well you should know the answer to that question. If your keyword density is to high to me it is basically just as bad a keyword stuffing.
Here is the video for your viewing pleasure.