Marner is worth a great deal more than this.

I would look to move one of Eberle, Schwartz or burakovsky in the marner deal. new team that will run into major cap issues with all of the players returning, looks like a 1 year hope rebuild that will but you in the trenches moving forward.
Dunn solid singing but maybe that should be closer to a 6x6
maybe could look at a cheaper backup option aswell.

For the Marner deal, you're probably giving up one of either Beniers, Geekie, or Wright in addition to picks.