Really? I have to MOD the game to fix a balance problem? I'm sorry, now THAT is just ridiculous.
I'm curious to know how this is exactly a balanced problem? I can happily run around using level 5 iron knuckles and drinking beer or popping a skull crusher candy and bashing heads with an iron sledgehammer (which is arguably better than a steel sledgehammer due to that longer attack animation).
I've went out of my way to make mods for this game that allow loot to not be gated, birds nests to be plentiful, gun parts to be craftable, and quality level 6 to be craftable. Do I feel it's "unbalanced"? No.
If that quality 6 which can have 6-10 extra damage REALLY unbalances the game, perhaps you should get better at the game. If you notice, "unbalanced" isn't the proper term here, I believe the term your looking for is "logistics".
For instance, why should weapon parts only be scavenged? How was the very first shotgun made if they needed shotgun parts to make a shotgun, but it's literally impossible to craft the parts? Because they're "logistically" gating progression and forcing the player to scavenge, in order to do.. what was that term again? Oh yea, craft. Which is a massive part of the game.
You act as if you don't get perk points in order to craft that higher tier weapon or armor DOESN'T give you stats that make you even deadlier while using them. That's the trade off of not crafting Q6 items. You can craft any previous tier, AND get buffs for the items as well!
I've ran into times where I've crafted level 4 items and scavenged level 4 items immediately after, but you know what that means? I'm progressing ALONG with the game, which is the perfect place to be.
If you dislike it so much you should either quit the game, try out mods (which can really make the game a lot better), or put on your big boy/girl pants and realize that we all have differing opinions and the developers don't agree with Q6 being craftable and do what is needed to get them. Let's not throw logic out of the window here, it's perfectly balanced. If you're looking for 1 hit kills, lower that difficulty and have fun with a sandbox environment! Play how YOU wish.