I didn't hear about the hook-up with Kelis but did read about the complaint about Bill's on-set behavior on Being Moral led to production being suspended. Bill Murray has had a reputation of being difficult to work with throughout his career and has had numerous blowups with fellow actors including Lucy Liu, Chevy Chase, and Richard Dreyfus among many others. One of his directors said he would never work with him again. His rep is that of a perfectionist and of wanting or demanding creative input. However some directors have praised him for his creative input including Ivan Reitman who in interviews said many lines in Stripes were non-scripted ad libbing by Murray, including the "That's the Fact, Jack!" Line which was written into the script at Murray's request or demand. Regardless of the conflicts, his coworkers and peers have also praised him as extremely talented both as a comic and dramatic actor. I think in the last 15 years or so his reputation caught up to him and slowed the pace and quality of his work. However he isn't exactly the only person in Hollywood who is difficult to work with.
I think I mentioned elsewhere that one of my past coworkers told me he ran into Murray at a high school football game when Luke Murray was in high school at St. Luke's and my coworker's nephew was on the opposing team playing St. Luke's. He approached Murray and had a long conversation with him which he said was cordial. He said that he didn't at all bring up Murray's celebrity, ask for a photo or behave like a "fanboy." They just talked about football and sports and he was very impressed by Murray's knowledge of sports.
As far as Kelis if he did in fact hook up with her, good for him. Wanda Sykes might actually be a better match for him from a comedic standpoint LOL.