Disagree 100% with the Wistia mention. Do you know how Expensive it is to pay for bandwidth for a video with 500,000 views on Wistia? To me, the original question sounds like he wants to make money now. Not spend money for some links to his website.

I know Moz is tight with Wistia, but I'm seriously doubting why this was marked a Good Answer.

If you are going for Virality (and you don't want to sell the rights over), use YouTube. Perform outreach to media outlets yourself. Get it on paid StumbleUpon. You can earn a lot of money with the Google ads on top of the video and you can still build backlinks in the process (if that's even a concern of his).

I would not be worried about the different URLs. Almost all url shorteners 301 to the destination URL and pass link juice. Even though the shortened URLs are different, they would all be passing the juice to the same spot.

watch?v=QMkltd6dZzU

You are right on. It can be very, very expensive.

Don't get me wrong, I love Wistia. I'm a Wistia customer myself. I just don't think it's right for every client/video/goal.

Use YouTube. Use YouTube analytics to find out what websites embedded your video. Perform outreach to those websites, asking for a link crediting you as the resource. Make sure the YouTube video is embedded on your website and the actual video description links to your website, to verify proof of ownership.

Great piece of advice on looking into building your own URL shortener. Not only can you guarantee it will be around, but you can potentially put some branding in there and stand out amongst the ow.ly, bit.ly, and t.co links.

This is the Average Position for your Search Impressions.

Example: Locally, you got 500 impressions at average position of 6.0. Nationally, you got 0 impressions at 122. It would report 500 impressions at an average position of 6.0.

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.