I think everything should be based on resistances but only to a point, you should always be able to cause damage to another player no matter their resistance/ac. If AC were to be removed and everything relied on resistances, everything should be reduced by the percentage of resistance + 2damage; which would allow lower level players to still stand a chance to kill someone without them out regenerating your hits. Which would make leveling physical good for prepping your weapons and base useful for hp and would allow all players to stand a chance in bmode. Although I do not play as much as I used to this would probably draw me back into playing gk and cause me to go from playing solely as a mage and putting more time into leveling/acquiring gear for melee. It would also allow for new players to go directly to bmode after about level 20 and be able to participate in pvp combat and actually be able to do a bit of damage even if it's not much.