I was optimistic when he was in junior, but his games in the NHL really, really muffled the optimism.The kid is 21 and has played extremely little hockey the last few years. As you indicated his trade value cannot be great at the moment so there really is zero upside to trading him. He need to play hockey. His skating is perfectly fine, his defensive game/hockey sense needs refinement (again he hasn’t played enough), but yes his biggest issue is strength. Hopefully he’s having a good summer but I don’t expect him to get there in one offseason.
In any case there’s no reason to be writing him off right now, even if I can understand some optimism about his ceiling being snuffed somewhat.
His skating would be "fine" if he were 6'2. But he doesn't have anything better than average straight line speed, acceleration, or edge work. As a smaller player, he really needs a skating advantage relative to other NHLers. He's weak on his skates too and falls down too much. He seems too reliant on others to get him the puck in scoring opportunities.
He's got one year left on his ELC and will really need a huge developmental year to be on an NHL-regular track.