I just spot checked a few domains I work on with TrafficEstimate.com and I would say that the website is not very accurate with their estimates.

I have not used Google AdPlanner.

Are you doing this as a preventative measure or had you already seen a significant drop in rankings before making this decision?

I would only remove them if they are on spammy sites. Then, focus on getting some more good, branded links to even out your backlink profile.

Adwords will help a bit. Many people don't click on Ads that often, and a video thumbnail is very enticing for a click-through. Especially one that appears negative.

Adwords is definitely an option and may help a bit.

Some other things I would try is to create a Facebook Page, Twitter Profile, G+ Page, Wikipedia Entry, YouTube Channel and Linked-In Company Profile. Official company pages on a strong domain like these, often has the ability to rank quite high and push down the other profiles.

Create these profiles and do a really good job filling them out. Full of information about your company. Then, link to them from your actual website. Build a few other easy links (comments, forums, whatever) to these social profiles. Get some link equity flowing their way.

Also, create your own YouTube video. Perhaps a newer video with a good title will push it out of that spot. Put the video on your website.

Good luck!

I think you are looking at your on-page optimization at too much of a granular level. Make the content as good as you can. Make it useful and make it a joy to read. If it is both of those, it won't matter if your KW density is 1% or 15%. If your post has a focused topic, it will naturally be optimized for the right words.

I'm not trying to say that KW research isn't important or that you shouldn't pick a few targeted KWs to work into the post. Just don't worry so much about ratios.

As for alt text, I would say that it is a positive ranking factor to have an image with alt text similar to the targeted KWs. I don't know how they would affect your tool's density percentage.

I wouldn't worry about removing these backlinks, unless you know they are paid or part of a network.

Instead, focus on building some good strong natural links through creating amazing content. The stronger your overall backlink profile is, the less likely you will ever find yourself in trouble over a few bad links.

Nathan- There is no right answer for this. All I can do is repeat the usual advice. It's quality, not quantity. Vary your anchor text.

Attempt to build some links that also benefit users. Instead of commenting, contact the niche blogs and ask if you can write a guest post. This will result in a followed link that adds value to the web instead of a nofollowed link buried in the comment section. Also, this will result in your product/brand being the focus of the site's readers.

Best of luck.