One thing that I dislike in the game is that very strict used Tier-progression on almost everything. It makes a lot of stuff easier, but I think it also makes it feel "unnatural" and "artificial". Some examples:
- Level of mobs. Mobs are strictly ordered into subgroups of mobs that have a levelrange of 5. This makes it easier on hunting e.g. trophies for your own level, but why shouldn't there be e.g. Cedar Treeants from Level 3 to 23 (then the 3 subgroups can be e.g. from 3-8, 9-15, 16-23). Or even make more subgroups from some mobs to increase the feeling of a bigger fauna in Istaria. This would also eleminate the need to move to a complete different area once you hit 20, but of course this would also mean to adjust many quests (e.g. the trophy tasks).
- Resources: As miner/gatherer I had sometimes the problem that my skill would have been high enough to gather resources of a higher tier at a good rate. But I needed to stay with the lower tier because I did not have the ability to gather this... make stuff like these depend on the skill, not the level. Also it would be nice to have new resources that are not strictly bind to a tier. E.g. a new metal that you need 300 Skill at least, and that is used for alchemy tier 3 and 4 stuff.
- Crafting stuff: I would like to see some stuff in the future that does not strictly needs resources from one tier. With the schools getting the primary skills where you don't get xp from processing resources you can mix this stuff up, and give it a more natural touch. E.g. some old recipes for the confectioner do have this already, and I can imagine this for stuff that are mostly decorative as well (new clothings, new different looking weapons).
- Equiping stuff: The only item ingame that I know that is not following that strict Tier/Level progress is the Dragon Claw. It still has a "all 6 to 7 levels" rule, but it again it feels more natural then the ordered 5-level weapon rule for all the biped classes.
The main suggestion from me is: Make new stuff less ordered and more chaotic in its rules. The ordered lines make the game easier to play, but it makes the game feel "unnatural" and "artificial".