Hi,

As Samantha said, you have to use the Mozscape API.
There are some programs that might help you (and some webs too).

Netpeak checker is really powerfull.

Hope i've helped.
GR.

Hi David.

Ahrefs.com offers that service: broken links.

Another way to do that search could be this: Downloading the historic backlinks list and with a mass checker, check where do they point nowdays. I've used GScraper and its option to crawl outbound links.

Best Luck.
GR.

Hi there,

tldr; There is no importance.

I have 2 things to say:

1. In 2009 there was a post and a video stating that Google does not use the keywords meta tag in web ranking.
   Post, Video
2. Personally, I believe that there's no reason to use them. There are a lot of "experts" that say you may not be 100% optimized using meta keywords. Other directly say that you will me penalized. As Google says it is not used, just dont use it.

Another idea is that this tag is public, so you may be saying publicly to your competitors what are your important keywords.

Best Luck.
GR.

Hi there.

I've found no SEO problems in hosting many sites in the same hosting space.

Best Luck.
GR.

Hi there,

The Rel=canonical will not de-index those pages.

To de-index, add a rel=robots with a noindex tag. And also add the rel=canonical or just redirect 301 the page. Of course, do it to those selected pages only.

Hope it helps.
GR.