I'd like it better if players can select between a nodestone (untradeable) or a Vanishing Journey Symbol for each Vanishing Journey Quest completion. This would make the daily quest a lot more viable.
I wouldn't say that there's an imbalance in-between classes. In-fact it may be too balanced that they're all sort of becoming equals. At this point there's only a few handful of skills that makes each class unique. I wouldn't go as far as to remove classes or make a world that rejects some classes.
I do believe though that the amount of worlds out there are too many. 8 worlds is a bit much considering the current state of the game.
In terms of Quests and Party Quest I seriously believe that they still need a desperate revamp even though they have undergone some changes. The fact that everyone trains and only does Party Quests for an item or event is extremely sad. Quests themselves most the time are not even that rewarding so a huge chunk of them can be avoided by today's game play. That sounds wrong and a waste of content.
I agree that the navigation is messy and there's a lot of maps. There's a lot of ways to get around though so I'm not entirely sure on ideas how to improve that. I'm not into removal of maps though.
In terms of upgrading and leveling system it is completely stupid. There may be a heck of a lot of different upgrading systems, and leveling may be easy from Level 1 to 200. The problem isn't that it's "too easy", but the fact that the difficulty of each part of the game is stupidly imbalanced. The jump between starting the game versus end-game is just absurd. At one point there goes a huge spike in what's expected in order to clear said content. I don't believe in removal and reverting back to the older leveling state and older upgrading systems, but I do believe that they definitely need to be looked into. Something is clearly wrong with that.
The economy is dead and dry not because of the lack of players. It's due to the massive amount of hacking going on for the past few years if not a century that has turned the value of mesos to be dead. I believe in order for the health of the economy of the game to recover is not only by getting rid of hackers, but enabling more accessibility or balance towards supply and demand. A healthy economy would have a large amount of exchange within the community no matter how much each player earns in the game whether it is millions of mesos or billions of mesos. The fact that a majority of items are either hacked or obtained through NX shows that the supply will always be low and possibly monopolized while the demand may be high for wants, but there will be very few buyers due to the costs being way too dam high. That definitely needs to be changed.
I'll agree with you that MapleStory isn't exactly in it's golden times anymore, but I see the source of the problems and resolution through a different lenses than yours.
I've also seen this occurring more frequently recently, more especially during/after bossing.
I decided to drop out of full-on bossing for a bit, and didn't have it happen. Then I started bossing again. Voila, it's happening again. It's likely not a Root Abyss, Hilla, or Magnus issue, as I still do those daily and haven't seen an issue.
It's not the content itself. It's most likely the game client failing to close unused information which eventually clogs up and crashes the client. That's my take on it at least.
If it was a specific content it would be very noticeable and most likely would've had a widespread complaint. A good example are Mechanical Hearts Event with the Wonderoids. But it could be a possibility so for now anything is on the table.