1. Potions/Ethers of all potency should stack to 99. (Elixirs excluded)
2. All HP recovery items should have a max use time and cool down time adjusted to match it's spell counterpart.
3. Add a phoenix down item into the game to allow Raise 1 on a targeted PC.
4. Re-evaluate the Stat increasing potions (i.e. Vitality Potion) for a possible increased potency.
5. Explore the idea of making potions/ethers usable on any PC.
6. Allow the use of consumables to be either unaffected by paralyze or not lost as result of being paralyzed.
Using potions & ethers is as much a part of Final Fantasy as riding a chocobo. The current incarnation of Alchemy and it's most common consumables are poorly executed in comparison to other FF titles. The balance in other FF titles revolved around using a character's turn to execute any action, however in a real-time combat system such as FFXI it's more difficult to balance consumables. I suggest that all consumables be taken under review and adjusted to match their spell counterparts.
Cure : 30~HP 2s cast/5s recast = no counterpart due to low level
Cure2: 90~HP 2.25s /5.5s = Potion: 90HP 2.25s/ 5.5s
Cure3: 180~HP 2.5s/6s = Hi-potion: 180HP 5.5s/6s
Cure4: 380~HP 2.5s/8s = X-Potion: 380HP 2.5s/8s
Having each +1 increment increase the potency by an additional 10HP healed (i.e. Hi-Potion+2 would heal 200HP or X-Potion+2 for 400HP). I don't feel having a potion equivalent higher than Cure IV is merited as Alchemy should only be possible to supplement healing to the same degree as a subjob.
I think ethers are doing fine in terms of the amount recovered but should have their use and reuse timers adjusted to lower the burden on use during combat.