I never dabble much with Alchemy, but the mechanics need to change. Leveling up was way too easy. One poster suggested that once you make a certain potion enough times, it no longers counts towards leveling.
I ended up using it a lot - I just could not help myself! But you are right: Leveling up was so easy that there was no reason to take it as a major skill. And once you got a decent alchemy set and skill, you had infinite money. Not to mention ridiculously powerful potions. I'm not sure the 'remember a particular potion' approach changes much, though.
- limited ability to sell potions (I mean, really, who wants to buy 1000 burden potions at 20 gold each)
- a more random regeneration of ingredients (so it isn't so much like clockwork)
- as a modder who makes plants and plant varieties, I'd like to see more types of ingredients and more varieties of plants.
- failed potions!
- the ability for potions to "go bad" after a period of time.
I like some of your ideas. I may want to raise you with:
- homebrew potions weighing x3 times as much as purchased potions (and a fixed weight, please)
- reduce the selling price of homebrew potions
- make alchemy sets really heavy (you would not take expensive lab equipment out adventuring)
- nerf the power of homebrew potions so the potions at the alchemy shop are more powerful
- some ingredients may make more powerful effects, e.g. healing potions brewed using a rare herb will last longer or heal more