Doubt Myers has much value to the Leafs. They have 7 NHL defensemen under control for next season. Myers would likely spend the season in the AHL before being owed a large qualifying offer for what he has brought. Doubt an NHL player would be going the other way for them and really that means the trade doesn't get done at all for cap reasons.

I just thought they were looking at him when he was assigned to the Marlies. I think a big part of that though was the extra 250k in cap space. Leafs could use any cap they can get and I can't remember when it was, but going into or during this year I thought I heard Kampf wasn't the best.

You're underrating how important Kampf is to the Leafs. He's a key PK'er, excellent face-off man, and anchored what was one of the best defensive lines in hockey this past season. All for $1.5m.

Kampf has had success playing as the Leafs 3C, used in defensive roles. He won't be going anywhere this offseason. And 250k cap space isn't a big part of anything even for a team that needs cap space. It's peanuts.

Why would Toronto trade Kampf?

That return to Toronto is underwhelming for sure.
Kampf to Toronto is what Hagel is to the Lightning. (though Hagel is the better player)
Kampf provides a lot to a team and the fact that he's only $1.5M makes Toronto decline this even faster.
Nashville should be giving quite more than that but obviously not to the extent as to what TB gave CHI for Hagel.

I think you're overvaluing Novak a little bit, but that isn't the crux of my comment. You mention that the Preds are deep at center, hence moving a center for a winger. Dallas is just as deep, if not deeper at the position right now. Between Hintz, Seguin, Faksa, Glendening, Dellandrea, Damiani, Johnston, Bourque, and Stankoven Dallas is set at the NHL level and in their prospect pool. Add into that guys like Benn, Pavelksi, and Peterson who also have Center experience, and that's really the one position that Dallas doesn't need to focus on this offseason

The Leafs have no reason to deal Kampf. He's the defensive stud 3C penalty killer they've needed for years and signed cheap.