What I think would be a nifty tool in Maple would be a character storage system
What I think would be a nifty tool in Maple would be a character storage system that holds characters when you do not have enough visual slots. The character storage system would allow storage of up to 100 universal characters (shared with all worlds except Reboot, which will have it's own storage of up to 30 characters), that can be switched out with currently placed characters. The Character "Cloud" as I'd call it, can also be used to store characters with deletion in process statuses and allow us to instantly create a new playable character without having to wait 24 hours because of the security reason.
Character Cloud Functions:
-Can be used to transfer characters across worlds (except to Reboot and Scania.). Characters in the storage can be transferred to any other world once per scheduled maintenance. Only one character can be transferred per maintenance. Characters in Scania can transfer to other worlds but can not you can not transfer characters to Scania unless your character was originally created in Scania.
-Can be used as means to bypass 24 hour character deletion to make new characters (characters awaiting deletion still have to wait the 24 hours, but will be in the storage rather than taking up character slots). This removes a lot of the fuss with people having to wait to make a new character if they used up their current slots.
-Can be used as an external storage to store items and up to 500m maplestory mesos. Characters with over 500m mesos must place excess ms2 mesos in the storage in the game within their world. (This is to prevent people from heavily abusing world transfer as means to abuse other worlds' economies. You will be abled to bring items over between worlds however to prevent a significant rise of meso transfers, the transfer limit is capped, and as noted above, the world transfer limit is only for 1 character per scheduled maintenance.)
This is a rough sketch of what the storage would sorta look like:
I'm not sure if this would be something players would want in the game but it's something I think should be available to everyone.

Mar
Shadower adding a "Shadow Stretch Skill"
How it works is simple: You can only bind 1 enemy (including bosses), and if it successfully touches an enemy, it can splash chain to other enemies at half the original attack range, binding up to 7 more enemies

Jan
Botters and spinners in Reboot
to find 20 of 20 channels on what is considered the 4-5 prime MapleStory mesos farming maps filled with botters and spinners.. then settling to do something else or going elsewhere where they feel their progress is hampered by the cheaters.

Jan
Maplestory Familiars Remastered
This is my idea summed up (the minor details are not to important). I feel like this, or something along these lines will really make familiars a more interactive and useful addition to the Maplestory

Jun
Suggestion - Party Quests Revamp
Now we face here another problem, if all of the PQs will be revamped so people will start one PQ then will move already to another PQ because leveling is easy today.

Dec
Add Permanent Nexon and Pets to Reboot CS
Reasoning: Reboot is missing a lot of things from its Cash Shop, and many people still haven't bought a pet or clothing yet because they're waiting for permanent deals.

May
Make the Job Change Tokens from the Gachapon tradable to anyone
Then there's "that guy" who sees the high levels that are paying 1b to job change and go "They're paying 1b, so let's make the price of these job coins exactly 999,999,999 maplestory mesos!