This thread seems to have lost it's way...
RE: OP's comment, I would say that an NHL roster is never something that is static and you cannot ever say that "it's done" being tinkered with. That said, there's also the issue of Kenny Rogers. You have to know when to stop tinkering on a specific area, but can't assume the issue is solved forever.
Now that the Leafs are a playoff team, they showed what they could do last season against Boston. They fell a little short, lacked the mental fortitude of a champion to get that little bit further.
Nonis (and new boss Leiweke) wasn't(weren't) a big fan of Reimer, so Nonis acquired Bernier. While no guarantee to provide greater playoff success, Nonis at least feels like it's an upgrade.
Likewise, the Leafs lacked in mental fortitude and the "knowing-what-it-takes-to-win" mentality. Burke had tried to address this when he acquired Versteeg, among others, but that didn't pan out.
Nonis came back at, and got Bolland, who to his credit has multiple accolades including two SC rings. And Bolland's Cup wins featured some real battles in the post-season that saw major attrition and took real heart to win, not least of all was the brutal finish of the exact team that flummoxed the Leafs in the post-season, the Bruins.
Those changes aside, the Leafs haven't solved every possible aspect of the team's woes.
Arguably, there are still concerns around C depth, because injuries can and will happen (and have happened).
And there are also concerns over the quality of the defensive corps.
Just because the Leafs are "in the playoffs" doesn't mean that everything should be kept as is. And likewise, that also means that the Leafs should abandon their focus on the future ahead of them.
The Leafs' prospect pool is still relatively weak. In about 4 years' time, the Leafs will need to have plans in place to replace key players in the current roster, such as Lupul, JvR, Kessel, Bozak, Phaneuf. If by that time, the replacements aren't already in the system, then the Leafs probably won't have those players developped enough to seamlessly insert them into the gradual holes that pop-up in the roster over time.
To a degree, that means that the current group of prospects are too old, in a sense, because they won't be utilized by the time their ELC's/RFA years are up. So there needs to be a plan in place to recycle these prospects, and upgrade as much as possible in the process.
So trade proposals that convert a player with current value to the club, like Matt Finn, into futures that give us another roll of the dice, will inevitably have to happen, because otherwise it's just a wasted asset. The timeline for these players has to be calculated effectively.
Another issue that further complicates this is that roles affect development, and consequently this affects how much time the Leafs have to find a replacement.
A player like JvR, for example, who is effective in front of the net and has the strength to be good along the boards, would take significantly more time to develop a replacement in the system than a player like Lupul who is more of a shooter type.
So even though Lupes and JvR are under contract for the same length of time, the Leafs brass have to have a plan in place earlier to replace JvR than they do Lupul. (And of course, if Lupul and/or JvR are still playing at the same level in 4 years when they're up for a new contract, the "replacement" can be them, but then what to do with the assets that would've replaced them if they weren't?).
The process of building a team is like sculpting the flow of a river. If you spend all your time just running with the current without paying attention to where you're headed, pretty soon you'll be way out to sea.