I disagree very much on the Weber trade looking good right now. He was amazing for the first two months and has had flashes of great play since, but overall he's several notches below Subban, and arguably not even the best defenseman on the team (Petry is a better possession driver and far less prone to getting hemmed inside his zone, probably one of the most underrated guys in the league). His even strength production is mediocre (again if we want to compare to Petry, who is a great even strength producer), and the biggest difference when comparing Weber to Subban, when Weber is on the ice, you're defending more. Subban actually battles for loose puck recoveries and plays an aggressive game. Weber plays conservatively which leaves him less error-prone, but in today's NHL is a net negative because in doing so you give the opposition more opportunites and limit your own team's, as he less often takes initiative and actually goes for the puck. The sad part is, he CAN play an aggressive game. He has pretty high success rates doing so. But he favours a traditional style. Weber isn't really better than Subban in any worthwhile way than being a harder shot and being more "low risk" (in quotes, because what good is it when Subban has better shot suppression stats in the end).
Also, Desharnais is barely even in our lineup anymore, and Plekanec is easily a great 3rd line calibre centre (although Phillip Danault would take that spot from him if we got a good 2C). So really they aren't problems either. Anyway, things Montreal mainly needs:
1. A halfway competent coach.
2. Price to be Price.
3. A 2LW
4. A 2C
Andrew Shaw is a great 3LW when he's not taking terrible penalties, and Lehkonen has 2LW potential but is not there yet. Pacioretty - Galchenyuk - Radulov is a pretty good first line, but most of our problems come from having no good second line quality players outside of Gallagher. A good LW - A good C - Gallagher would leave us with a 3rd line like Shaw - Danault - Byron, which we've tried before and has worked wonders. 4th line would be Lehkonen - Plekanec - Mitchell would be a pretty pesky 4th line. However, the chances of us landing all this without hampering the current roster in some way is slim to none, and not something I'm holding out much hope for.
But realistically, Therrien has to go. He's an awful coach. Problem is, Bergevin is his best friend. Therrien should have been gone long ago, but it'd take a god damn miracle for him to leave this season. Missing the playoffs or getting destroyed in the first round might prompt him, but even then I'm not so sure. All I know is the window is closing, and the chances of us being able to do anything about it are very low.