This is a sure way to achieve a nothing build that's not good at anything. You can exploit weaknesses of bosses with any specialized build, you don't need access to all and every weapon out there. Strength builds will have plenty of choice for different types of physical and fire damage. Same with Dex, with lightning thrown in. Arcane have statuses, and good physical damage options with occult. Int and faith caster builds have incredible choice of spells to cast, with any kind of damage including physical. You don't have to have Jack of all trades stat spread to utilize variety of weapons and damage types. Speaking of underrated power stance options - omen cleavers. You can farm for them right at the start of the game in stormveil. Whatever affinity you put on them doesn't matter, because they get maximum swag points for being some of the coolest looking swords in the game.

Also, speaking of quality affinity. You need high stat investment to make quality worth it. If you spread everything thin, and have as much str and dex, as in int, faith, vigor, endurance, etc you're not getting anything good out of quality affinity. It doesn't make it scale from all stats. Only relevant ones.

I'd probably stick to levelling 1-2 damage stats for each half of your run. If you level equally you're damage is going to stay low for the majority of your run. Don't forget your vigor as well. The only weapons that scale equally off the 4 main stats are Sword of Night and Flame and Rellana's Twinblades.

Uh, I see your use of quotes, but Quality affinity weapons are specifically STR + DEX. Furthermore, they aren't particularly viable unless you are around RL200 so unless you're in NG+, you're going to have to sacrifice other stats to make it worthwhile and even then you'll probably still lose out to single-stat prioritization. Leveling all stats equally will just make it even worse.

For dex and str, go with powerstance and one has to be lightning infused and the other cold infused. For faith and int: there is the staff of great beyond, that scales very well with int and faith (and can cast any spell or incantation).

Piggy-backing.

Quality builds are fine, but I wouldn't spec your weapons for quality until RL 200+...

Pick dex or strength over the other once you've found a weapon that fits your playstyle, then upgrade that weapon.

But, yes, your choices are limited... buuuut, a lot of cool peeps here would be willing to give you a fully upgraded weapon if you ask nicely.

The more I consider this, the more I have to grudgingly agree with everyone saying not to do it. After plugging some things into the character planner, a Flame Art Smithscript Greathammer will outperform the Godslayer's Greatsword, and a Magic Smithscript Axe isn't too far behind. In other words, I could invest solely in INT or FTH and still achieve comparable damage.

I mean, I kind of knew that, I guess I just slightly underestimated how bad it would be. You would think investing in, say, three different stats for a weapon would end up beating out a different weapon that only requires one stat, but nope, doesn't work that way.

The "correct" name for this would be "Mundane build", DS2 had mundane infusions which did exactly this (scales with your lowest stat thus forcing you to level them all equally). I'd agree doing this would be more of a challenge build but IMO being versatile is still generally better than being a one trick pony. It's gonna take a while before you could use the really good weapons of any one category with stats spread so thin but here's some ideas:
- Reduvia has fairly low requirements but is kinda obscure as a playthrough tool because only bleed build players level Arcane and they tend to be PvP focused
- Dragon breath incantations have pretty low requirements and can be boosted with an early game talisman + Highlander Axe, ailments are gonna be the best way to deal with lower raw damage so Frostbreath and Rot breath should be your first two unlocks
- For your final melee weapons pick Celebrant's Skull, it's a surprisingly good greathammer for its low requirements and the extra rune boost helps with all the levels you need to get
- for your offhand I suggest Meteor Rod (no upgrade cost), the dragon communion seal and whatever shield you fancy (Coiled Shield for another ailment tool perhaps?). Spell wise Rock Hurl is a good allrounder, Glintstone Icecrag another ailment tool, Flame Grant Me Strength plus putting Prelate's Charge on the skull grants a surprisingly powerful combo... or Flaming Strike for good general utility.