By Robin Lundberg Is Khris Middleton’s health a concern? Will Giannis prove to be the best player in the NBA? Here’s what the Bucks are facing this season. Here are the biggest questions facing the Milwaukee Bucks this season. Did they need to make more moves?The Bucks have a championship core. But the roster is getting older, and they didn’t make many moves to add to it. Joe Ingles was the marquee addition, so they are going to need him to play well and the others to stay healthy if they plan to return to the NBA Finals after being eliminated by Boston last season. Is Khris Middleton’s health…