Simple question: if i am skilled in one of the above abilities, am if i am able (with an Enchanting-Shop) to extract and refine poisons or do need a chemical or medical skill for that? My mage has the surge quality of "natural poison" and acc. to RAW i should be able to extract my own poison for enchantings that require the poison of an animal, am i?

Arcana and the Enchanting shop allow you to process the venom in a way that will preserve, focus and concentrate it's mystical properties, but does not cover the collection process beyond "things not to do".

Since you produce the venom in your own organism, I'd suggest a First Aid test or something like that the few first times, or alternatively finding someone with the skill to teach you the correct procedure even if you don't have the skill.

Also, gross.

And I'm not sure a SURGEd metahuman will count as an animal for something requiring animal venom.

Refining poisons I would think takes a medicine or other sciency-related skill.

It depends of the purpose of the refining.

If you want to stabilize the toxins to be able to store them at room temperature, gelify them so they stick on a blade, all the while without loosing their potency, yes, this is the realm of science skills.

If you want to process them to produce alchemical radicals to be used in enchanting and other magical purposes, then it's alchemy and the Arcana skill.

Unless you are going for magical goods, I would go with chemistry. It seems to be the make drugs, poisons, bombs skill.

You know me. Of course i want it also for blades and my SURGE-claws.^^ Thanks all for the answers.

Use chemistry, an additional knowledge skill in poisons might be useful.
May I suggest the following as well.

You have natural venom already
You are immune to it

Get a Chemical Gland
Extract the poison you have
Install the chemical gland that produces your own venom.
Have the chemical gland to pump out a constant dose into your bloodstream

Here are a few new questions: If the poison is contact based…

If I have a constant dose of poison in my bloodstream – do I sweat it? Am I a constant danger to people since I could poison people by possible touch?

Yuck, who would waste an implant getting the venom they already have?

The difference is that instead of it being within a naturally grown gland it would infact be within your very blood.

bleed on anyone with your contact posion...