Not a Utah fan, but I watched Kesselring a bunch in previous seasons, just haven't watched him this season. But I have been on the Utah board and I don't think he's as good as you think. I watched him at the WC this year after the season and was impressed as well and thought he was good, and I think he might have a higher peak than Samuelsson for sure. But he's absolutely not a defensive stalwart. Offense and puck moving is his bread and butter, but he isn't the type of player to handle one on ones against top talent and I haven't been particularly impressed with his board play or play without the puck either. Samuelsson is exactly the type of defensive d-man Utah should be hunting for, if he ever regains his form and stops being constantly injured it's a very good low risk high return play.
Personally I think that will happen. If you think it won't then I can understand not wanting to trade Kesselring for him.
As for Quinn + 1st for Schmaltz, that's a home run slam dunk. Schmaltz is an extremely one dimensional soft winger who needs to be in the top 6 to have any impact and is often a detriment defensively who also is often just a perimeter player. I don't think he should fetch a 1st, let alone Quinn. I think he probably would get something like a 3rd + lesser young player or maybe a 2nd.