#1. Vegas doesn't need to clear his salary "outright". They are under the cap, and wihle depth has obviously taken a hit, any deal can almost certianly be money-in-money-out.
#2. Call me crazy, but I think Pietrangelo has enough respect around the league that he'd have positive value. He's won 2 cups with 2 different teams, playing massive roles for both. He was a 24:00 defenceman for the Knights this year.
Now, his NMC will of course get involved and likely limit the value a bit... especially as he's seemingly unlikely to go to a team like San Jose or Columbus. From a family perspective, St. Louis would seemingly be an ideal spot; but not really from a hockey perspective given that they need to get younger on the blueline.
That being said, as a Leaf fan, I'd jump on this... would love for it to be OEL + Robertson... but that's a bit of a tough go trading a guy the day after you sign him.
Then go and flip Marner for a cheaper forward or two to free up the cap space.