Alright let me explain you something. There is a big difference between what is fair and a balanced game.
It's important to know that actually most people of Gunz (no matter what server) do PvP. So, knowing this obviously Quest will be a little bit dead with the player base we have right now.
PvP players have been asking to make Quests a mode for win Lucky Boxes items with limit days for make them play this mode. Thing which i thing we all here are agreed is a trash idea. (If any PvP player is reading this, the reason is simple. This will remplace the actual drop system which is good for questers. If you want donation items you have many ways to get them.)
So, maybe increasing the chances of getting a mythical (1% to 5%) will make some people play some bosses for grind them. But the problem here is THE BALANCE. Before, legendary was the max tier, and lvl 15 was the max you could get. We are talking about that max PvE DMG was Avalanche x2 lvl 15 = 78 (And Iron Crow x2 = 66). The legendary in that moment was 1% of chances to get. Now, not only that we have 30 iLevels for each tier, also WE HAVE 5% TO GET A LENDARY. Tier which before was the max tier. But if that isn't enough, now we have Mythical. Tier which is OWER POWER in all quests, and for a tier like this, is good that it can be balanced with a low chance to get it. In all games as less chances you have to get it, better item it should be. This is literally an universal rule for every game that has an item drop system, aka RNG system.
So, what's the point to make it 5% if it is bettee than legendary? Tier which i gonna say again, was the best before Mythical release. There is literally no point on this.
Now, about your expirience revamp suggestion, let me show you something.
Actually, Cat in the hat gives 50% extra expiriece (Yeah, it's 50%, not 25% as the descripltion of the item says). Add to that 50% 100% extra of 10 activity points. Knowing this, let's convert your expiriences:
Goblin King: 400.000 Experience (Cat hat = 600.000, Activity Points = 1.200.000)
Fake Goblin King: 400.000 Experience (Cat hat = 600.000, Activity Points = 1.200.000)
Thunder Goblin King: 400.000 Experience (Cat hat = 600.000, Activity Points = 600.000)
Dwarf Goblin King: 400.000 Experience (Cat hat = 600.000, Activity Points = 1.200.000)
Palmpoa Commander: 450.000 Experience (Cat hat = 625.000, Activity Points = 1.250.000)
Zombie Queen: 400.000 Experience (Cat hat = 600.000, Activity Points = 1.200.000)
Zombie Queen II: 400.000 Experience (Cat hat = 600.000, Activity Points = 1.200.000)
Zombie King: 400.000 Experience (Cat hat = 600.000, Activity Points = 1.200.000)
School Quest: 500.000 Experience (Cat hat = 750.000, Activity Points = 1.500.000)
Giant Lizardman: 500.000 Experience (Cat hat = 750.000, Activity Points = 1.500.000)
Broken Golem: 600.000 Experience (Cat hat = 900.000, Activity Points = 1.800.000)
Palmpow: 500.000 Experience (Cat hat = 750.000, Activity Points = 1.500.000)
Jeez, all of these quests are above one million exp. And i'm not even adding the 30% extra exp of sacrifice.
Main problem with this (apart from the point is so ****ing unbalanced), PvP players were craying about how over power was scrider and how fast was it for level up (because all they can is complain on quests, ofc). I even remember they were ****ing happy when hang was fixed the 1st time. Knowing this, i don't wanna imagine the rivers of tears these crybabies will make with these expirience revamp.