I doubt it'll result in substantive change (it never has in the past), but lets play along for fun. As a product owner in real life, let me put on my product owner hat and give some suggestions on how I would resolve some of the issues.
1a. Hunting Zones
Situation: For my level (108 Maestro + 109 DoomCryer), SV would be the ideal spot for hunting, as it would be for probably 500-1000 other players. Because there are only a dozen or so spots, we have to go to the next spot, Tanor, which is also packed. Alligator? No spots either. FoM? No spots. Basically after I'm done wasting 30-60 mins looking for spots, I end up in Isle of Prayer which has yellow mobs to my DD.
Before the 2x xp event and dragon weapon event, I made around 50t-75t per day. With event I was making 130-150t. With new update, I made 25t with a dragon weapon. Thats 10t for IT + 3.6t for Castilla 110, and hunting all day.
My XP rune is expiring tonight, I will not be renewing it unless things change. Also cancelled my prestige rune. Its just not worth it.
Action items:
Add more hunting spots for level 105-110.
Roll back the change to SoS level.
1b. Raid Bosses
Raids are something fun to do with your clan, something to break the monotony of afk grinding all day. By making them too high even for the highest players, you removed all end-game content from 100% of players.
Action items:
Bring back the raid bosses to their previous level. The lv 116 bosses rarely got killed, but those could've been a stretch goal for a clan to reach in the near future. At least keep the stretch goals realistic, and keep plenty of content for the majority of players.
1c. Party Experience
Currently there is no incentive for bringing support classes (healers, tanks, and isses) except for the few instances where you absolutely need them. Increase the pt xp bonus to add about 90% xp more per member, to encourage people to bring full parties. If I can make 2b xp per kill solo or 1.8b with a pt full of clannies, I'd be happy to make a full pt.
2. Augment System
Augmenting items from anywhere is nice. Having to go to the blacksmith to remove it makes it redundant. Augmenting armor adds a bit extra bonus. Requiring an item that hasn't dropped in a long time in the recipe is ridiculous.
Action Items:
Allow us to remove augments from anywhere. The role-play experience of going to an NPC for this was fine 16-years ago, with the latest updates there is no role-playing elements left.
Remove Energy of Destruction from the Armor Augment Stone recipe. Or make it easy to obtain these items.
3. Item Changes
Adding sigils/shields to every class doesn't really add anything to the game.
Level 4 seed bracelet and augmenting books is to rich for my blood, don't know much about either, and I'm 100s of billions away from caring about them.
4. Skill Changes
While a lot of people were jealous that Maestros could solo yellow mobs, the kill speed (1 mob per 12 to 18 seconds depending if skill mastery triggered on Last Attack) meant you would do so very slowly. I felt that made up for the fast that we kill green and white mobs slowly even with very respectable gear.
Action Item:
Remove the level damage penalty for everyone. If you are strong enough to handle an area / mob, you should be allowed to hunt there. Re-balance stats such as accuracy/evasion/attack/defense to achieve this purpose the right way.
5. Other Changes
The player experience of going from level 1 through 105ish is fine with the exalted gear, etc. However the level 106-113 game play is unfinished. When we get a new clan member and help them reach 105, we eventually need to have the awkward conversation that unless they can spend 200-500$ to get some gear and magically make it to lv 108+, they can't join mid-level content (party dailies in Aden, IT, etc.) unless one of our higher level members who can solo that content runs them through, and they contribute nothing and just try not to die too often.
Action Items:
People should be able to get enough gear to do content of their level using in-game functions (i.e. hunting mobs for adena/drops). That means you should be able to obtain R99 gear around 105, and r110 gear by 108/110, using only things obtained by playing.
Either bring back SoS or increase the regular mob experience to make up for it. People need to feel they are progressing towards something.
Introduce some non-trade easier-to-obtain versions of some of the better items. For example killing a field boss could give a 5% chance to everyone who killed it to receive a non-trade epic. This makes it feasible for people to gear up with perseverance, while not affecting the economy because the tradeable epics will retain their value.
Events
Events created by NCWest are too expensive. It takes 200-500$ at the very minimum just to have a playable character for mid-level content. Then a few 1000$ if you want to reach level 110+ content. Many events have items that would statistically cost over 100k$ to obtain. Its not unusual to spend 100$ on an event and obtain nothing. While it is not legally required to post the odds in North America, it should be an ethical consideration taken by NCSoft. For random chests, there are too many worthless items. If you're going to pay 1-5$ for a chest, getting yet another useless rose is just a slap in the face. When 80-90% of the items you receive are a slap in the face, its not encouraging to keep going.
Also there are too many items from evens that cannot be traded or have an expiry date. Letters are currently not tradeable, making it harder to complete words, and allowing lower level players to sell their letters. Then many rewards are non-tradeable and completely useless, like our clan leader receiving 3 spiritshot packs on his archer.
Drastic changes
Merge Isses + Tyrrs + Tanks with a stance to go from dd mode into tank mode (with at most a 20% p.atk penalty while in tank mode).
Merge Healer and Nuker classes where you can change stances from one mode to the other, similar to inquisitor mode, but by turning into a full nuker.
These changes would give the same leveling ability to support classes as the other classes.
Quality of Life
Melee attack lag and the JuJu agathion spam should have been made a much higher priority. These are the nagging things that drive people insane for no good reason.
Bottom Line
While whales are definitely lucrative, don't forget the power of numbers. If you improve the game and make it popular again (FF XIV is an example who achieved this), you could easilly be raking in 10x or even 100x more revenue from L2 even by lowering the ncoin costs and making the game more accessible / fun.