part 3 concept should work, if you store a color skin(arms red, feets blue, groin-stomach purple, chest green, head yellow) then through the hit detection it will check one of these colors, then if it hits red then it will hit the arms and damage lets say, 10, if it hits yellow which is head it will damage 100


through code you should be able to scan which color it detects on that skin, lets say its named hitskin then tell the code to scan that skin for the colors,
if you want random damage on head or the other parts, like this
if yellow(head)
78....100(or higher if you want "overkill" damage) then have like a random(20)

if you want random damage from different weapons this should be a function inside every type of weapon. just change the values inside the damage part.

this is just for filling out the third concept