I think I can asnwer 1 & 3.
1. Kongo is fighting Herring because everybody thinks has a suspect ground game and Dana is giving him this chance to prove all of them wrong. Plus the top HW"s are busy(Big TIm, Big Nog, Randy)
3. I saw an article on mmafightline.com that he was offered two fight but both fighters got hurt. They didn't mention which fighters. Dana said he was talking to him for a fight in april or may.
I think Tanner just wanted time off because he wanted to get his life back on track. I heard he had drinking problems. I'm not sure that's the whole reason but I heard that was part of it.Hoped that helped!