I agree that Nurse isn't some black hole possession-wise... but in my opinion he's getting paid way too much. Offensively (both possession and production) he's a dynamic top-15/20 D at ES. But defensively, my read of him through the 'eye test' (and the numbers appear to back it up) he's pretty poor - in the same ES defense tier as Hronek, Q. Hughes, and Bouchard - none of whom should be mistaken for a defensive stalwart, that's for sure.
Coupled together, he's probably a decent #2... but next year he's going to be paid like a no-doubt #1 (I'm sure I don't have to remind everyone that he'll have a top-10 - among D - cap hit next season)... and despite the hand-wringing he's actually having his best season by GSVA at age 27. We might expect him to gain a bit of ground in the next 2-3 years, but expecting a decline around 2025 isn't that far off-base.
I personally think that his offensive talents are currently wasted on a team where he's getting under 30% of the powerplay time. Maybe the Oilers should entertain a move of either of the other two offensive-minded points (-not Bouchard, preferably-) and grabbing a complete ES D to complement Nurse. A more nuclear route would be moving his massive hit to a team that needs an offensive-minded blueliner and use the return plus cap savings to be a deeper, harder to play against team.
I defer to Oil fans as I'm less confident in my assessment than I would be for a more familiar Eastern Conference player but I'd still make the argument that A.) Nurse is a good D who's still probably going to be overpaid by ~$2m next year, B.) His talents are a bit redundant given the current makeup of the Oilers' blue line. Were I a fan of Edmonton, I'd want to explore all of the possible solutions to this conundrum - especially if an early exit is the result.