Nice idea, doubt anyone has even tried this out or tested it.
Now I used to use Delirium on my Rogue... it just helped out, HOWEVER, that 1% or so turning my rogue into a Doll was annoying... oh yeah... ranged attacks from monsters are annoying for a Rogue merc.
Now as for other mercs ... look up monster modifiers... I am not sure about worn item modifiers giving attributes other than Auras.