As for LRC I am not aware that JR has blacklisted them. I post their articles frequently and to date have had no problem. I know many freepers do not appreciate LRC but many others do. The site does not focus on the war exclusively by the way, there are many interesting articles on economics, history, culture, etc. There was one on the origins of Mother Day I was thinking about posting.
If by sister sites you mean Anti-war.com, well as I understand it they requested that their articles no longer be posted on this FR but I do not know why.
I think JimRob's objection is mostly with the fact that these sites write explicitly to get mentioned on FR, anti-war.com's self-righteous complaints not withstanding.