Theoretically yes, Majin Buu could beat Beerus. In some billions fights, the chance that Buu could win at least 1 time isn't 0… But that would be so unlikely that we should state that he couldn't. There is a gap between them.
Beerus doesn't care about Buu. Kid Buu is no where near Beerus's level of power. In fact, it's a good thing for Buu that Beerus didn't run into him during one of his mass destruction runs back in his Majin days with Bibidi.
Raw power wise, Jiren is overwhelmingly stronger than any form Majin Buu has ever had. It would take, literally trillions of Kid Buu's to harm Jiren, whatsoever..
Hashirama is far stronger than Tobirama. He is the reincarnation of Ashura and have Wood release which is able to suppress the Nine Tails chakra. Tobirama invented many jutsus including Reanimation jutsu and Flying Raijin.
Mito UzumakiThe Couple. HashiMito (柱ミトHashiMito) is the term used to refer to the romantic relationship between Hashirama Senju and Mito Uzumaki.