He was being tasked with becoming more of a dynamic offensive player in Hershey, yes. There have been glimpses, mostly using his speed in transition and leading the rush. I would expect him to be more along the lines of a healthy Kempny than a defensive defenseman initially, mostly because I'm not sure he's got the man strength yet. He's also not super tall/heavy naturally compared to, say, Alexeyev.
He missed the mark as a solid partner for Carlson going forward and wasn't amazing, no. But he was vastly more accomplished than whoever will be replacing him unless Chara does return.
I don't think it was just goaltending that let them down. They did let in some weak goals at times but also regularly bailed them out of stupid mistakes and glaring breakdowns. I'm of the belief generally that it evens out and, again, as-is I think they're just a lot more likely to give up more than they did. The game has changed but they need to be able to defend the crease/home plate area and relying on Orlov to predominantly be that leading component isn't enough. I do think they will give him at least the opportunity as-is to PK over Kempny. He's ready to take that on and they're going to need that from him on this roster. I have to imagine they want Chara back, despite his weaknesses, given just how much emphasis they place on team toughness. What to do with Kempny remains the most mystifying situation. I would have thought that the other second rounder would have been used to dump him and perhaps add better depth. Maybe that happens yet.