I like the idea of a progressive system so we don't have to rush or rather can enjoy the lower lvl content a bit too.
I do have some issues with some of the following tho:
By the time Hellbound is enabled, we don't really need Inquisitor + Vanguard anymore. It is mostly used to conquer the early levels (in my opinion) before party play takes off.
Stage 6 is even after Hellbound opens up.
I don't want to start leveling a lvl 55 Gwolf when Im already lvl 80 on my main. Not only will it not get exp, but it will level very slowly.
If I make a normal wolf lvl 80 and transform it to Gwolf later, it will still delvl back.
I generally agree Folei's suggestions, even if the implementation of those doesn't have to be 1:1. It just reflects a general idea of where the problems lie and what could be fixed.
Besides that, my main concerns are:
-Buff Boxes. I know I am one of the people who abused those the most, but I also hated doing it. You could argue that you simply have to find a party, but that just doesn't work out too well either. To only rely on finding a party to play with means a lot of down time and not being competitive with those who have a constant party or can solo/duo more easily. I am strongly in favour of having only 1-2 chars, just because I don't care to dual box anymore. As Folei said before, I envision a Buff system like the newbie buffer, where you can only receive buffs according to your own level (e.g. at lvl 40 you get lvl 40 PP/SE/EE whatever buffs, which progress up to Prophecies etc.)
-Pole Partys/AoE Exp. We all know those partys are the way to go if you want to level up fast. But they are also the main reason why no one wants to play in a real party and why everyone reaches max lvl so fast. It might be controversial, but I would like to have the Polearm nerf which reduces VR from every monster hit after the first etc. (dont remember when that one came, but it exists) so doing massive Pulls in 4s or the likes will be a lot harder. You should not be able to Pole 2 rooms with A grade common, no Boss jewels etc. If you are a Warlord and got a live Healer with you, you may do as intended.
-Raids need to feel like Raids again. Previously Raid Bosses were only about being first to kill it. I have killed countless Raidbosses with my Titan, nothing else needed. While it is fun to do so, it should be more of a Clan activity and involve fighting other clans for it. Not simply being there a minute early.
I know the part about Raidbosses is hard to balance because early you can't even do them without wolves (for subclass etc.) but later when you have Vesper they die really fast. Maybe we need a hard-mode for Raidbosses.