On Barry:
It's still very early in the season. With the youth on defense (esp. Wyatt, Walker, Slaton, LVN) and the guys returning or ramping up from injury (Gary, Stokes), there's a scenario where the defense makes a lot of progress over the course of the season.
I think he is getting blamed for a lot that isn't really his fault. For instance, Detroit's first TD drive, LaPorta snags a ball in tight coverage and Rasul just falls off him instead of making the tackle. Then Douglas bites on a pump fake, can't recover, falls down, and St. Brown is wide open for 6. I guarantee you that after that play, there were Packer fans the world over texting each other "fire Barry." But that's not on the coach; it's on the player. But fans, psychologically, really struggle to blame players for anything.
That's not to say it's all good on Barry's end. It isn't. On the second Detroit TD, the alignment basically invited the touchdown. You had Wyatt lined up as a 3T and Smith was a super wide 9. The C gap was a massive canyon even before the ball was snapped. The way the defense was deployed didn't even give them a chance.
My gut is still that they would move on from him after this season. And I think that's for the best. Barry strikes me as a guy who, at his best, can give you back exactly what you put in. He is never going to elevate his players and make them more than the sum of their parts. But it's not a huge deal, given that this is a developmental/assessment season anyways.