k2 Kunena and comments

1) Yup. Full K2 integration for automatic Likes & Comments was added in the most recent 3.4 release. For the full features in that release, see:
www.sourcecoast.com/blog/extensions/face...e-support-for-joomla
2) It's done automatically, but you can select specific categories or articles that you want to include or exclude as well so that it goes on just the right articles.
3) JFBConnect works with jReviews just fine, in that users that are created through JFBConnect are seen just like normal users to jReviews. To add Likes, Comments, or any of the other social widgets, you'd have to use an included module or add the {JFBCLike}, {JFBCComments}, etc tags to the description of the product or to the jReviews template itself.
4) Kunena support for 1.5 and 1.6 is included, so you can import avatar and parts of the user's Facebook profile into the predefined fields of Kunena.
5) JFBConnect creates standard users that can be used by any component. If you have specific questions about how it would work or integrate, just let us know, and we'll help answer them.

Thanks,
Alex