Could mana be rebalanced / reworked?

Currently Mana feels weird: the main function of mana in video games is to limit the use of expensive skills like comet and to discourage skill spam.
The developers also decided to limit player power by making high level skill gems to be much more mana expensive.
I find these functions contradict each other: to balance mana cost to limit expensive skill usage one needs to have predictable mana costs. E.g. there is a mana pool large enough to cast 3 echoed comets and then I run out of mana for a while. However the skill gems level makes mana costs highly unpredictable: 170 mana cost for a comet can easily become 300. The player is encouraged to use as high level skills as possible which can easily lead to a constant mana potion chucking playstyle. I do not consider this to be fun, since there is no meaningful choice involved: I keep spamming my expensive skills anyway, I just need to press an additional key to drink a mana potion afterwards. Furthermore there are ways to massively tilt the mana economy in favour of the player: stats like mana efficiency and certain spirit gems can lead to the experience of having near infinite mana.


My idea is to rebalance mana in the following way:
-have constant mana costs across all skill gem levels (player power and "+skill gem level" likely need to be adjusted to work with this change)
-give all classes the same 1000 mana pool
-give skills a minimum mana cost and a percentage mana cost: e.g. comet could have a 30% and a 700 Mana cost. A comet consumes 30% of your mana pool, but at least 700 Mana (if the 700 mana is higher than 30% of your mana pool, more than 30% will be consumed)
-rework all mana related stats (e.g. mana regeneration is independent of mana pool size), rework mana potions and spirit/support gems to support the new system, e.g. mind over matter could just give additional energy shield based on mana pool size to decouple effective hp from mana usage, remove mana efficiency as stat, mana potions and spirit gems should complement and not break the base mana economy, so no constant mana potion spamming as default playstyle, align fate (druid) could make the imitated skill free to cast and select only at least medium mana cost skills, mana remnants only drop from rares (no constant free mana supply, but it feels more impactful to pick up a remnant),...

benefits:
-skills can be balanced based on a predictable mana cost, the developer can design the game knowing the player can cast exactly 3 comets before running out of mana
-different builds can be balanced around different mana economies:
if you use skills with a high mana base cost, you want to get a large mana pool (e.g. for the 700 cost comet, it would be 2334 Mana = 700 / 30%)
The player experience would be: I can freely cast my cheap skills while having to intentionally plan when to use my expensive skills. After using up my mana pool it takes a while to regenerate it.

if your build consists of skills with a very low mana base cost, but percentage costs still matter, it could feel more like an "energy resource" in other games (something like Kennen in league of legends): the mana pool is small and the mana regeneration is really high. Mana influences more moment to moment gameplay: it might prevent me to cast 3 high %-cost mana skills in a row, but it quickly regenerates, so I'm never really out of mana.

There could also be builds where mana doesn't really matter.

I could also see this as something that might contribute to balancing triggered skills by placing a soft cap on spam-ability.

I think mana is fine. If you're having mana issues, the problem lies more with your build and gear choices. Nearly every game ever invented pretty much relies on the basic rule - higher level skill/spell costs more. More payment = more power, or rather more power require more payment.

Much of your post just feels like you want to gut mana and have a warrior's rage-like mechanic which isn't a good fit. Mana potions are extremely underpowered as a resource recovery, but you typically want to offset that with affixes on your gear like mana regeneration, mana efficiency and recover %mana on kill. These affixes are extremely powerful as you gain more mana and pushes players to build their chars accordingly.

how to say you're having mana issues without telling us you have mana issues.