I may have said this elsewhere, but I just thought I'd put it here because it fits and I'm also not entirely sure I have said it elsewhere. I think that the dex mod should be added to melee attack rolls instead of the str mod, then make weapon finesse give you the dex mod to damage rolls. If you think about it, it makes sense. A guy with 18 str and 5 dex is going to be able to hit things really hard, but he's so clumsy he can't hit what he's aiming at. Str affects how hard you swing your sword, dex affects how you swing it. Weapon finesse could then be used to use your high dex to hitting the right areas to do more damage instead of just hitting hard wherever.