Dex is for that irrelevant.
You are going to have penalty of other sort.
Like a bad aim.
Point of this is to have sufficient strength so you can use the weapon without it being too cumbersome for you.
If you ever tried to shoot a bow that is too "heavy" for you. Your arms start to shake as soon as you come to full draw. No dexterity in the world will help you if you do not have muscles to hold the bow steady so you can aim it.
Well thing is i have bad ranged "accuracy" and while i can easily "wield" a pool cue or darts or a badmonton racket, my accuracy with such is for crap.
You allow for dex to be used for ranged attacks (which acknowledges it plays a role in accuracy) and yet you seem to not see any sort of minimal dexterity threshold like you want to use for other attacks? That is very inconsistent.
Also, you mention pulling and holding a bow - what about loaded crossbows? is their damage dice limit supposed to reporesent the strength just needed to hold them up - since there the pull and shoot are very different things?
heck, why cant a strong guy be clumsy and slow with his sword too? Strong and powerful does not equate to accurate or well-timed - a very powerful blow swung at the spot i was just in... well lots of good that does you... wait what is the stat that affects timing of stuff - yeah its dex.
If DEX applies to chance to hit ALL attacks - as you describe when it is take the higher - why then does STR alone become the deciding factor for "based on this you might suffer a DISAD for your attack roll" if indeed the goal is to open all weapons to all classes?
Why not say "must have a DEX or STR equal to X or better to avoid disadvantage" or ""must have a DEX AND STR equal to X or better to avoid disadvantage" if the actual goal as stated is to open up all weapons to all classes and provide an ATTRIBUTE mechanic for making them effective.
That stated GOAL does not include "and make strength great again" or any sort of preference for strength over dex so why then do you see it as good for it to so favor HIGH STR builds over HIGH DEX builds - which this system definitely shifts towards?
You mention a half-orc wizard with str 16 and int 14 iirc - well what about an Elven wizard with 16 dex and 14 int - shouldn't that also get as many weapons available as the orc if the goal is to just make weapons available ability based and not class/feat based?
or is the goal really to give more to strength based builds and less to dex based builds? cuz, it does that.