since there's no actual way to fix Fallout 4's hardwired fuckups (Dialogue choices, voice acting, consequences, etc.), might as well try to focus on the more popular things Bethesda advertises (and never gets the shit right), which is weapons, action and weapon modding.
-Dual Wielded Unarmed (seriously, this shit with the right hand only thing is fucking stupid, even the bethdrones in the forums agree it's an idiotic idea to only wield one unarmed weapon in one hand, as there's absolutely no negatives in Dual Wielding brass Knuckles/Power Fists/Deathclaw Gauntlets/Boxing Gloves).
-more melee/unarmed weapons (seriously, these categories have the potential to have thousands of unique, awesome weapons, and you only shit out 4 for Unarmed? For a company who states they're creative, you fuckwads sure are lazy in design, Bethesda.)
-More melee/Unarmed Weapon mods (Melee/Unarmed are also the most potentially creative mods in the game, and could use more options, such as pure damage mods (heavy handed Power Fists or so), attack speed mods, hell, even mods for when you block an enemy attack, there's a nice amount of things you can always implement.
-better melee system, but good luck with that.
-more love with guns in terms of variety and mods.
Anything else is gravy, but if you're gonna make shoot em' up/hack and slash, at LEAST make it enjoyable.