Those numbers seem about right. Marchment and Marincin in the A gives them 1.6M tonplay with. One of Kappy or Johnsson will need to be traded to upgrade the RD.

These rumours scare me..

I like Muzzin a lot, but with limited cap and 3 LHD already on the team, it seems weird to pay Muzzin that much...

Would rather roll with Rielly Sandin and Dermott on the left and invest in someone to play the right side.

Unless Dermott is going to be traded

Issue is Sandin night not be ready for a shutdown role, Rielly isn't suited to it, and Dermott is a 3rd pairing guy. He can play the right, but more likely he gets traded. Liljegren becomes RD3, Holl is RD2, now need an RD1 and an LD2. Muzzin is the LD2. With 1.3 or so left of cap, you trade Kapanen as part of any deal. Frees up about 4.5 overall, that's what your RD1 has to make. Unless Johnsson is out, too. Then you have wiggle room.