So I've been trying out a thief studying the poisoner path...

Is the only way to tell the actual affects of a poison to try it yourself (and also make an antidote)? Then does the antidote have to be the exact same ingredients...or how does that work?

Also, how does it work when combining ingredients? I tried combining ingredients that both made one kind of poison and I got a completely different kind. Is there some kind of logic behind this, or is it simply trial and error (so many possible combos!)? How likely are multiple ingredients to produce better vials (vs. single ingredients)?

Emetic poison seems pretty straightforward. But can someone explain what the impacts of fear poison are? How about neurological poison? What do these actually do to other players in practical terms. I don't have a good sense about what they actually do so not sure how they should be used.

Do better/stronger poisons have different types of impacts, or just last longer or do greater damage?

Thanks for the help.