1. No, they come back looking like they did at the time the sample was taken but he didnt have a sample for Kisame yet and now cant get one.
2. Wrong again, The Sword of Totsuka, also known as the Sakegari Longsword (酒刈太刀, Sakegari no Tachi; Literally meaning "Sake Cutter Longsword"), is a variant of the Sword of Kusanagi. It is sheathed in a sake jar; the blade is actually the liquid inside the gourd that is released and shaped, rather than a conventional sword. It is an ethereal weapon, with an enchanted blade capable of sealing anything it pierces. Those who are stabbed by the sword are drawn into the jar and trapped in a genjutsu-like "world of drunken dreams" for all eternity; by extension, Itachi also managed to remove the Cursed Seal of Heaven from Sasuke by stabbing and removing Orochimaru from Sasuke's body. Orochimaru sought the sword for all his life and Zetsu commented that he could never find it.
3. You have no proof Hidan is dead. As He then informed Hidan that the forest that they were in belonged to his clan, and that they would ensure that Hidan remained bound to it for eternity. Finally, having a chance to avenge Asuma's death, Shikamaru lit a cigarette and tossed it at Hidan, causing the explosive tags to detonate. Hidan was literally blown to bits. As Hidan's remains fell into the pit below, his detached head promised to kill Shikamaru in any way possible. Shikamaru caused the pit to collapse, trapping the screaming Hidan beneath the rubble. He was buried in a place Akatsuki can never reach and thus he is no longer considered a member.
Hidan is dying slowly from a lack of nutrition. When Kakuzu is reincarnated during the Fourth Great Shinobi World War, he takes Hidan's absence as proof that he is still alive.