How long do you think he should still be Hab? Are you looking for a ceremony to highlight 1000 games played? Plus/minus is the worst stat possible to measure anything. Of course he's not used on the PP, his stick is where offence goes to die.
This team is poorly constructed as your post indicates and most NHL clubs are built on offence driving their third lines, not a shutdown center like Plekanec. Defence can be taught, offence comes at a premium. If some other team is prepared to pay a decent price for Plekanec, you have to look at the big picture -- this team is not on the cusp of a rapid turnaround. There will be pain and it's will be for more than one season. I don't know what value a Plekanec can bring to a team who is in such dire need of change and especially one that is starved for offence.
It used to be that teams were built from the back end first, goalies, Ds and defensive players. Now, that business model has been inverted. You build from the front, with offensive players first and foremost.
I don't remember anyone saying how the Habs's downfall and main issue in the past 3 seasons, has been not enough defence-only forwards.
I think one more year. That gives Poehling time to develop amd mature. Danault another year of playing with pros.
The Canadiens need to improve their PK. Trade Pacioretty and Plekanec and you have more holes to fill. +/- is a stat started by Scotty Bowman. Still a good measure of play. If you are taking defensive zone draws regularly, not a minus, and your wingers are producing, you are doing your job.
For me, I love the idea of signing Backlund. Put him between Lehkonen and Gallagher. Could possibly get 20 goals out of each. Backlund-Lehkonen gives you a top PK duo.
Byron-Plekanec have been a good defensive duo. That gives Julien two defensive options, both can be effective.
I try to build Galchenyuk-Drouin-Sherbak up. I think acquiring a Gaborik could help the two wingers in their careers, make them both 25 goal scorers, in practice. Sherbak especially because his game reminds me of Gaborik's.
Deslauriers-Danault on a 4th line, donne la fougue. And a 3rd PK unit.
I think the Habs need to be a 4 line effort. This year's draft is the future. I am not sure Plekanec gets more than a 3rd, so it's a crap shoot at that point anyways. I use Pacioretty to fill two holes, going forward, and the dearth of draft picks to get prospects to replace players on this team.
I hope Julien Brisebois is the guy at the draft table though.