It's far more likely as you've said already that BA will take on projects and problems he likes the look of. But I think he also wants a young talented player as was widely reported when Vancouver came calling last year. Maybe with the draft around the corner a 2nd will sweeten the deal for him.
I think you're somewhat overstating the value of cap space in isolation. OEL is not getting traded if doing so creates an even bigger hole on defense and a bigger problem for BA. He needs a defenseman back or some younger talent.
I'm talking OEL+Fischer for Myers, Roussel, Eriksson(B/O) & 40th overall. Saves Arizona a ton of salary and saves Vancouver a ton of cap space (in year one, year two it's a slight uptick, offset by Beagle's expiration, and then year three the cap goes way up).
Gives Benning a big upgrade on D, a shiny brand name acquisition, and frees up capspace for him to shore up other areas. Gets his neck out of the noose. Beyond the next three years, what does he care? He's on his last leg.
Meanwhile BA gets more budget room to sign players, has fewer to sign (Myers and Roussel) and gets a third 2nd round pick for him and his brand new staff to use in their very first draft as a team. He also ditches the 4th, 5th, and 6th years of OEL's deal when it's going to be especially bad, just as he starts to look to compete.
EDIT: This is just an
example of the
type of deal I think we'll see (if any at all). Short term GM dumps short term trash for short term upgrade. We see it all the time. I think the keys are that the Coyotes save cash money, move on from OEL and get at least a little something for the trouble.