do you think that hisagi is a strong character? and should be promoted to captain? WHY? plus do you think he is hot?

Yes, perhaps one of the strongest among the vice captains (somewhere around Renji). No, he shouldn't be promoted to captain. He's not as strong as Kenpachi by a long shot, and he doesn't have bankai. I suppose some might consider him hot, though I don't focus on that.