Keeping my thoughts in order to the very questions at hand will be tricky.
Of the recent updates, how far back do you want to hear? Not a fan of condensed patch notes, or notes where there is content that appears without notice. Unfortunately there have been times where I have been curious about how lazy the developers were during RED and beyond. I don't see much inspiration these days, just a case of sizzling without the trappings of a good barbecue (i.e. actual food).
First thing that came to mind is the Haunted Mansion revamp. I just didn't care for it at all. Something about both the change in content and layout felt much like the Alien content of Masteria as an unwanted mess. I would have gladly taken a repeat of the Madhouse over the event. Even the events from when MapleStory first started had more flavour.
Could also argue the same thing for Chryse being converted from a nice little area to visit to a lacklustre party quest. Segue into another little thought with the current set of party quests looking more like a poorly tended graveyard. The cross world party quest is a nice idea but looks like a condemned prisoner walking the last steps. Of course that also leads to the lack of fun the party quests seem to have these days.
On the other hand, Secret Stories was actually a nice change of pace. I do like taking a run through lore from time to time and it felt like something that would have been better as content to go with the old Madhouse event. Though the "Blockbuster" format concept is starting to get rather ragged with overuse.
Maple Music Festival, I'm sorry that bit of content was just terrible. I just did not care for it at all between the bullet hell and overabundance of etc. drops clogging the inventory. Could also say the same for MapleRunner.
The thanksgiving event unfortunately is another that happens to fall short in execution and timing. Executing the same event ad infinitum and would have been more in line if it was aimed to be about a month long given the time of when the two holidays happen in Canada and the US.
About the classes to date, the best one I could speak for would be Fire/Poison and Battle Mage. The F/P feels like someone in Korea forgot about poison and relied too much on fire. I hated teleport mastery and the addition of final attack as current mechanics for both sets of arch mages. Given with fifth job coming soon, I'm not endeared either to seeing another fiery skill in my loadout. The general fifth job skill for thieves feels like it would have been a better fit with the damage over time element. In other words, had more fun as a master of hell without the excessive emphasis on being a pyromaniac.
As for the overall changes with the skill Magic Guard, the change to toggle felt like it should have been done before the "normalization" of the buffs. The time where the skill had a 6 minute duration felt like someone was asleep at the helm.
The battle mage to me felt like someone was lazy and called it in while sick. I have the least amount of fun with said class due to the current mechanics feeling like the designer did it while on a hangover after finishing a night out at a dance club. To be honest, the concept is one where the paperwork does not fit the reality for some players.
The world tour event was nice, though there were some ugly things about it. Namely the bullfighting event which some classes could cheese through with certain skills. The other mini-game from the event being pinball felt like a reskinned version of an event we had some time ago. Ugly thing about it is being less like a few tables from the eras of either mechanical or solid state and more like a wood rail machine without flippers.
Some of the boss changes like Magnus adding damage over time or the 30 second revival counter as quality of life? Quality of life with those two changes alone feels like a real detriment for those who don't have the best equipment to work with. There have been times before the recent update to reduce the client size where said mechanic would mean one life gone before even getting to the boss due to lagging on entry.
Now it feels like either bosses can have mechanics that either work well for a bullet hell shooter; they rely on enough mechanics that rely on the abuse of one hit kills; or cheap combinations of stun and percentage of health attacks. Some of the patterns used by Magnus and other recent bosses feel like there is a struggle due to enough garbage on screen to even recover progress.
What initially drew me into MapleStory was the art and simplicity. I have played other games that tried to emulate the formula as a side scrolling MMORPG and failed in certain aspects of execution. Maple to this day still has a charm that has kept me playing since the English beta went into service.
On localization efforts, I would say it happens to be hit or miss. Some of the more recent content from Korea feels like it hits the wrong target like having areas that are too flat or not really targeting the levels that are missing content. Other pieces will miss to the point where either it is abused or neglected to the point where finding a Burning Area at maximum level is not much of a challenge.
Maybe one could consider having some of the Korean developers take time to play GMS out in the field. What works for a smaller region doesn't always work for a larger one. Perhaps trying to pick the minds of some of the private server developers on the tactics they use to deter botters. I would even suggest hiring those on whose methods are more kin to a white or grey hat hacker. Sure Korea might hate it, but there are times where it is easier fighting fire with fire.
That is all I can think of given I was stretched over a few hours of thoughts that bubbled up.
Might be one commonly suggested option given to move the retro/retired sets to another location.
Another option I could think of is inspired by an area in World of Warcraft known as the Caves of Time. Certain areas were revisited from the series cumulative lore and turned into either raids or instances. Given that the concept isn't an entirely new idea. I would toss that with a few of the books from the Choose Your Own Adventure series, namely the Cave of Time book and the sequel Return to the Cave of Time.
Hence why my thoughts about what we have as retired assets being re-purposed for another area.
Oddly enough we already have a bit of lore that is already similar to said area with the Grand Athenaeum or Helios Tower entrance to Ellin Forest. I'm sure there could be a way to use the old content and make it into a new area that revisits the retired content for newer players that haven't experienced it. I know we had something similar with the old event where we got to mess around in the old maps and it would actually be a nice break from seeing the same set of maps ad infinitum.
I'm not saying keep the same levels, given we have a fair bit of low level content for those who do bother to take the time and explore. Just to play around with the concept is what could be considered given that it would be something that could come after we have the 5th job release.
Not saying that it has to take the form of an exact replica of the original theme dungeons or party quests.