Hi there,
First of, I myself haven't played an alchemist or similar charakter in LARP but I had the honor to watch one of the best (in my opinion).
1.
The world/system of Mythodea is not exclsuive, so you can of course play with the experiences your charakter made in diffrent worlds. As I usually play a mage I know it's sometimes difficult to "translate" the spells (in your case recipies) one has learned in one system to another. Sometimes you get far more experience points in one system than in another resulting in diffrent ranges of skills your charakter could choose. Just use common sense (like you already wrote yourself
), then it'll work out fine.
2.
Glas is fine. There are beltpouches made from thick leather that protect small glasvials quite well even in combat. Of course it's always better to use glasbottles that look the like but I have also seen empty boozebottles (the very small kind) being used. Those of course might raise an eyebrow or two but considering that good looking glasvials are expensive and might get lost easily (or wont be renturned) I'd consider them okay on an event as big as the Conquest.
3.
Water with foodcolor is absolutely okay. Any other edible addition is usually also okay. Just mention the "ingrediences" somehow to the player that is either carrying the potion or drinking it, so that there will be no misunderstandings about allergys.
4.
I'm afraid I have no experiences in this area.
5.
I reccomend to visit the Fortress of Diversity in the Wayfarers Quarter. They have an alchemists guild there and the afore mentioned awesome alchemist player. I'm sure Baron Fireblade will be happy to share some of his tricks.
And your welcome, it was a boring nightshift anyways
Lumian,
Bodyguard and seasoned warrior.