I dont think you can shot while paralysed 
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Also seems right to reduce accuracy on poison and fire. With acid yes the argument can be made indeed, but making sense is just a small part that does not justify it alone. The real one would be, if improves the balance of the game, then should be done.
I agree on poison being underwhelming, in fact Im not sure poison should be a separated system at all. I can see regular poison being replaced by acidic poison that in addition shreds armor in later game (acid). I mean, poison in game is not a gas, so I guess it is absorved trough the skin or when penetrates the body. In fact it could be a cool chance for evolution mechanics, poison is after all an evolutionary trait, with qualities that range from blinding, to neurotoxicity, paralisis or dissolving organs.
Chemical warfare is neat!