Leafs decline flames

Both bad trades. Nylander is the second best Leaf right now (argument for first, but Matthews has been amazing too) and he has 21 pts in 14 gp, on pace for 123 pts. You don't trade players like that for a good #2D, #3D, #4D.
Klingberg has been so bad that a 3rd probably isn't even enough to dump him... and MTL is the wrong team to send him to

Patrick Kane isn't signing for no $1,000,000 in Toronto.

Zadorov and Tanev are the only real possibilities to Toronto. Hanifin wants the U. S. Only and blocks Toronto with his 8 team no trade which included the other 6 Canadian teams.

There isn't a team in the league who'd eat 4+ million for a 3rd round pick, let alone the Habs when it's the Leafs asking

Yup. Considering many people suggest a Campbell dump from Edmonton is worth a first (and he only makes $700K more than Klingberg) AND any first round pick from the Oilers is looking like it will be higher than a Laffs first round pick then the Leafs would probably need to send a first with Klingberg to get rid of him

Difference is Campbell has 3 more seasons after this one while Klingberg is only this season. Monahan to MTL is a more accurate comparison, so a 2nd is likely the most it would cost the Leafs.

Let's be honest. Just like Campbell in Edmonton, I truly think that Kilngberg will be put on waivers first and foremost, and then sent down to the AHL for a *breather/reset/conditioning/confidence booster*, for about a month.
A month later, he will be back, play a little better, and then he may very well be shipped to another team for good ol' Future Considerations (even with a little salary retention - Leafs have their 3 spots left).