would there be a way to swing Dellandreas RFA rights to Washington as part of the deal too? or is he pretty solidly set in Dallas?

He's a pretty solid asset in Dallas. Not going to try and blow smoke and tell you that he's a future all-star or anything, but he's a cheap bottom-6 forward that plays a very good swiss army knife kind of role. He can play up and down the lineup & in just about all situations. Not saying he would cost the world if Washington wanted to trade for him, but I don't see him being added to a deal like the one above.

This is an interesting idea, especially now that Washington has cap space. Think this depends on if Leonard is up in the NHL next year. If he is, there's not really room for Leonard and Miroshnichenko to play with Dadonov in the mix but if he stays at BC for another year Dadonov could be an interesting Pacioretty replacement, assuming the Caps don't bring back Pacioretty.