Not a chance we are giving up Carlsson as he's a solid prospect that should break into the lineup next year. Furthermore, the Hawks are not in a position to take on cap dumps.

We would gladly take back Steen if you guys ate Nylanders cap hit. Chicago could add a bit too.

6x7.5 is realistic for Petro? My word.

I'm not sure why the Blackhawks would do the Blues a favor and give up a prospect for a cap dump in order to give the Blues enough space to sign Pietrangelo. The Blues would need to sweeten that deal quite a bit.
For example, bringing up a painful move for many (if not all) Blackhawks fans, in order to move Bickell a few years back it cost Teravainen. In order to move Sharp, the Blackhawks threw in Stephen Johns to Dallas.
And isn't Steen a bottom 6 forward these days?

Gotta think Dunn gets more than that

It seems you are overly optimistic.

Steen has full trade control, and there's no way he goes to a rebuilding team with likely one year left in the career. I don't blame him either. He's a legacy Blues player, and why would he not just decline the trade and spend his last year on a contending team? Plus, if Army can convince him to retire a year early, that probably sets him up with an executive job somewhere within the Blues organization, which bodes well for his family long-term.