I have some comments on your suggestions:I do agree with the above statement, but I have seen many people want pvp back. Despite how unbalanced it may be [funded people will probably win], many people still enjoyed it. Also I'm pretty sure that maple can implement a stat modifier system to equalize the damage of characters and their stats [similarly to league, smite, overwatch, etc.]. In that way, nexon has the ability to see clearly how to control buffs and nerfs of every classes [and the number of classes shouldn't be an excuse since the other games have to deal with balancing over 100+ characters, maple has around 40 ish]. This is my opinion though let me know what yall think.
1. It is not just a matter of level that determines how easily a character can clear a boss - funding is the major factor in most cases. A problem with many bosses is that there is such a large disparity between "normal" and "chaos" that often makes normal to be too easy and chaos to be difficult or impossible.
2. The level burn you mentioned was only an event, so players do not always get to speed through the dungeon levels. Without the burn event, a player can clear most of the low level dungeons without being over leveled. However, I do agree that there needs to be more high level dungeons, especially at 160+.
3. We actually had 2 iterations of PvP in the past. The first one was relatively balanced since funding did affect damage, but of course there were still some very overpowered classes. The second one was definitely unbalanced due to funding playing a role in damage. Even without including boosts from equipment, it will still be very difficult to balance classes since there are so many of them.