Spell sets for potions would basically be a way to do an action by using an icon with a potion or substance.
Imagine alchemy, for example, being the only skill that your character is going to have. So, you could isolate the ideas or turn all of the different spells, for example and use them through alchemy.
An example: Drink a potion could equal incognito or change form.
Another example: An action, like imagine your character is able to pour the potion onto something for an affect. So, we could just add to that by clicking the potion and then targeting the object.
But there also could be different ways of pouring the potion. For example: A circle of fire or a wall of fire.
It might sound redundant to use the same things over when you already have them in other groups but it would actually give you more in my opinion and allow for a wider range of different possibilities.
Another thing to consider, is allowing the skill to go above 100 and scale the power of the potion by base level for 0 scale to 120% increase, plus allow bonus to stack which would create a very powerful, diverse skill.
If it was done right, it could be similar to being in Ninja Form, where if you're using a potion, you're not able to do anything else until that action is complete. For example: alchemy only potions.
Like, creating a character who would use potions only to heal and to combat, who would be powerful like a mage but possibly able to summon or even turn himself into a type of weapon, like a dexxer.
So, if you began to mix, for example, poison and alchemy, poison being the skill that would simply modify any type of poison potion. When you think about that, you wonder why they couldn't just add a group for each. For example: We have poisoning because we look at it as being an action. So, why not look at all of the other resistances as being actions.
For example: Physical being on the top of the list could be similar to poison but it would deal in physical properties. So, you could have a basic resistance to physical attacks, a higher cap to your physical resistance, possibly a damage modifier for physically attacking someone. So, then any of these could give a bonus to alchemy if the potion dealt with the physical hit, for example, just like poison would increase the affect.
As far as the main attack for an alchemist most of us probably look at the explode potion but imagine our affectiveness if first the explosion potion was more powerful. I remember playing this game where the bombers threw potions and the people would just blow up into pieces. So, you could set 2 of these guys on the hill and just blow up armies, their weakness was, they couldn't move as long as they had the bombs set.
But imagine other techniques like freezing a large group of people or dowsing a large group of people with gasoline, making them vulnerable to fire. So, basically you would just need to ignite the people then with fire wall or fire ball and then the whole group would ignite into flames.
But I think if you really looked at adding a system like that, you would add some type of icons and possibly even certain requirements, such as having 2 types of potions to create 1 or throwing 2 different types of potions for a unique affect.
You could definately add or tie into glass blowing and taming. I think alchemy would probably reach into any skill.