Please take your time and read my entire post before posting any comments or criticism, I also would highly appreciate if developers would take a look at my post. Anyway, lets start.
What we have now is problems with mana, unbalanced damage, certain skills, attributes, potions, items, class roles and the list goes on.
One of my biggest concerns are the potion, mana and attribute/skill problems at the moment.
I'll try to keep this short.
Almost every class runs out of mana in just 20 seconds or so, and has to keep potting that mana to keep on going.
The healer role is currently literally non-existent, who needs a healer when I can easily out heal incoming damage with potions?
More and more, we see weird builds, enchanters and warriors running around with crossbows and daggers, that doesn't make sense.
Now you might say "why? it does more damage", yes it does, but is this "working as intended"? I doubt that.
Also, although warriors received a buff recently, my 2h warrior still hits like a napkin, and does less dps than my lvl 15-something archer.
Items are just very confusing and partly make no sense.
These problems are not only because of the way items were designed, but also because of the current attribute system.
There are too many stats, that go together with too little attributes.
If the developers plan to keep 3 attributes for all the current stats, well I doubt it's even possible to balance it out unless they make each class stack 1 attribute.
Eventually we/they have to introduce more attributes or get rid of stats.
Skills are another point that I consider a problem, and I would like to talk about potions here as well.
Instead of us having to keep spamming the potion button constantly, we should work around it.
I have some ideas, I don't mean my way is the only way, I don't really care how they fix this, as long as it eventually gets fixed.
Currently each class uses mana as their resource, with potions we have unlimited resources, which means we can keep on going as long as we want, we can just spam our best skills that cost the mana without any consequence.
One way of working this around could look something like this for example:
Add a ~30 sec cooldown on potions (keep on reading please), have something similar to a rest function which could be used while not fighting, maybe 5-6 sec after using any ability that helps a party member or damages enemies, we could dig deeper on how this could work without problems, but I just want to sum it up by saying, similar to to the way threat works now just the other way round, kinda.
Now our problem is running oom too fast while fighting, we could work this out with adding abilities with something close to 1-3 min cooldowns, that recover mana and possibly some hp instantly, or over time.
These abilities combined with reduced mana costs on skills and wise potion usage, would result in a more fun and interesting gameplay.
This is my point of view of the game right now, there are other minor problems at the moment, but in my eyes these concern me the most, and I won't bother respeccing or buying expansions before therse crucial points for gameplay get worked around.
Edit: Since people are against having each class have its own role, why not make the same dungeons in harder difficulty, with harder monsters etc, that would require an organized group, rewarding more powerful loot and rewards. This way every group of the community is satisfied.