I don't think Fitz is done adding pieces, frankly. Of the three names you bolded, I think Kuokkanen has the greatest likelihood of starting in the NHL next season. He's the ripest of the bunch, and Zajac immediately took him under his wing following the Vatanen trade. They'll be great together on the fourth line next year.
Boqvist is an interesting case, especially now that Nolan Foote is Devils property. Kuokkanen, too, to an extent. I know Fitz loves Boqvist, but I also wonder if he'll be shopped. He could be an attractive ELC option for a cap-strapped team that unfortunately needs to dump a good player for cap purposes.
I also hear that his brother's organization is officially rebuilding... under the direction of an incompetent moron...