Don't panic sell Karlsson. He hasn't had a great start, sure, but he is more than capable of pulling it around and ending up in the 60-70pt mark. The season is young, he's adjusting to a new country/team/style, getting his family settled etc etc. It'll click; form is temporary, quality is permanent.
As for the trade itself, Bob is a lot better than Allen, Prov is a lot worse than EK, it evens out into you both improving one area to hurt another, which would be fine if your roster is D-heavy. But I'd hold back on any EK trades myself...