WordPress.org

Does this plugin add any database tables?

No. The link and a small bit of associated data is appended to the comment content at the time of submission

Will this plugin work with Disqus/Intense Debate/js-kit?

There is currently a version available for JS-Kit (Echo). Intense Debate and Disqus may be suppported soon.

I am having a problem getting it to work

You can submit a support ticket at http://comluv.com