1. Speakers were people with a special sensitivity that allowed them to receive vague visions from the Traveler. The last Speaker didn’t have the gift but instead made his mask that allowed him to get those visions. So technically, anyone could fill that role if they have the mask. Currently, there was a hint that a new Speaker is alive. I believe someone is looking for the candidate. Crow is a possible one, as he’s been reached out to directly. The visions weren’t really that helpful. It speaks to people so vaguely, it’s almost pointless. Another Speaker will come up in the future, likely in the lead up to finally meeting the Gardner. 2. Hard to say without cultural references points, it’s whatever you make of it. A society that prizes strength and competence would value those along with appearance. 3. While the instances of a Ghost having more then one Guardian are too few given the number of Ghosts without Guardians to say with certainty, it’s possible. It’d be an easy narrative step, sure, but I find there are way more instances of them not finding a second. But like you said, plot device.