Re: double Equipment cards
the rule says "There is no limit to the number of Upgrade cards a Hero
may have, and they are all always in effect."
However, what happens if a hero equipe several times the same item: does the bonus/ability stacks ?
ex.1: 2 x "Ice blade: +1 die and +1 def in fights in your space" = "+2 dies and +2 def in fights in your space" ?
ex.2: 2 x "Hazmat suit: cancels one success from fire or corruption" = "cancels 2 success from fire or corruption" ?
ex.3: 2 x "Rail Gun: you gained Ranged" = "Ranged +1 die" for a non-ranged hero (get ranged, and then get the +1 die" or "+2 die for a ranged hero" ?
From the way the rules are worded that would be the logical conclusion.
You could just view it as an upgrade to the respective item, e.g. a refined Hazmat with better stats.