So i won't speak on moonstone expansions for the cooking profession, as I have not done the math yet and I am VERY sleepy, but I do have a couple of words to share about the mining profession expansions.
A player starts with fifteen slots for mining in the first area, which I feel is absolutely fine. There's only two ores to be found if we do not include the moonstone ore. However, a minor issue arises when a player reaches mining level 12 and suddenly there are three ores found in the newest location (moonstone ore excluded of course).
Consider if with the fifteen slots someone gets incredibly unlucky and gets 4 of every ore due to RNG. There are only three slots left of the allotted starting slots. Yes that's one spare slot for every ore to make it still manageable, if not resource depleting. I do not know the amount of time it takes to reach the spooky spires without wheels to speed up a player's minecart, I have not yet unlocked said area. It starts to be a bit harder to manage to make decent progress in ore collecting and smelting. Perhaps that is intentional, i do not know.
And it would be fine, i think, if this was the most amount of ores available in Lorwolf to obtain. however, there are still three more locations to unlock through profession advancement and in the very next area there is a whopping FIVE ores to obtain. If we consider the incredibly unlikely but super unlucky scenario as before that means it is actually impossible to progress this profession ever again unless 25 moonstones are obtained to expand a player's capacity once. this does not account for moonstone ore drop rates. And I think it would be incredibly unfortunate if this were to ever happen to a casual player who cannot buy moonstones and also does not have the time to farm moonstones through playing the game regularly.
Perhaps there is a failsafe for this scenario in the game's code, but perhaps there isn't. And there is, as far as I see, no way to dump a player's haul in the situation that this happens.
All things considered, I understand why moonstones were the go-to for expansions, however I also think that the first expansion for these professions that expand through moonstones should be done in pebbles. at least with 20 slots, this situation of so many ores can be mitigated. And if I may offer some numbers to end this suggestion.
I have played lorwolf every day since full launch, I only have 7 moonstones to my name (please disregard my custom apparel on my lead wolf, that was a gift from a friend).
I can however, through regular play, get 10k or so pebbles fairly easily. If time playing and revisiting are in any way issues to this site that damage ad revenue or whatnot, I think it would be fair to have this expansion around this much or maybe a little more. Honestly I need to run more numbers vs time in my personal playing sessions.
Apologies for the length, I think it is important to be thorough.