I'm not seeing the upside for the other team in any of these trades. I think Colorado is already good with 25 year old D men that good enough to be healthy scratches.
How is that Oilers trade happening? Are they calling Bowman asking how can they get Murphy on their team? If it's Bowman calling them, it's from a fairly weak position because if Bowman is shopping Murphy the other GM's know Q isn't going to play him by the end of the season. It'll be like when Bowman had to trade Daly to the Penguins and got back an expiring contract instead of even a bottom pair D man.
I suppose the Penguins might be interested in Hartman if they were desperate for a spark.
The Buffalo trade isn't well thought out. Evander Kane is a 30 goal scorer (granted he hasn't gotten there lately due to games missed). Even as a rental Buffalo is probably going to look for more than a couple of AHL'rs that are called up in case of emergency.

They are not 'in case of emergency' they are quality prospects that can play in the NHL now. Hawks have too much depth to play them and it's also a second round pick for a rental