Really, you are aware of that hockey is a team game? Way too early doing these kind of judgements about Karlsson, that's for sure. Karlsson is being "forced" to a slightly new role this season not optimal/perfect for him, having to prioritize defense more and not his offensive play. Karlsson is feeling his responsibility right now for sure and its not the right time focusing on his offensive play. This is not the best way utilizing a player like him but I don't think the Sharks have a choice right now. It's like saying a world class elite goalie is bad when letting in goals playing for a poor or struggling team, you have to be careful pinpointing a player like that, it's not that easy.
Pavelski is a totally another story, an extremely tough loss for the Sharks, it was sad. The Sharks is a different team without him. Thornton too even though he was more important in the looking room last seasons (a great guy and leader).
A good chance both San Jose and Karlsson turning this around, not too late (the opposite comparing to the Senators).