I shoot fairly well in game. I get maybe 30-50% hit rate with my weapons. The AI seem to nearly never miss. Each fight I'm probably shot 20-50 times. Is there any sort of global setting(s) in game that can be easily changed to make enemies miss more? Like a LOT more?

I don't remember enemies in FO3 being this accurate or doing so little damage. It's very frustrating.

I think a good test for this would be to make an npc with guns 50 and one with guns 0 and compare the bullet spread of each of them to see if skills even affect their aim.

I'm pretty sure bullet spread impacts AI aim - the problem is that AIs always aim directly for their target's center-of-mass, and with bullets as fast as they are, that pretty much means their only source of inaccuracy is bullet spread, unlike a human shooter.

FWE had a means to change the skill formulas. One of them allowed setting it up so that the gun condition had a direct effect on bullet spread (which honestly makes 100% sense to me) in (or in replacement) of a damage modifier.

Because the NPCs tended to have poor-to-mid condition equipment, this ended up causing a significant reduction of accuracy in regards to enemy fire.

I wonder if that required FOSE... if not, it should be entirely doable...
(and honestly should have been done to begin with... obviously the ones in charge of this have never cared for a real gun, or don't care for that kind of realism)

that is easily changeable in the geck by altering the settings called fweaponconditionspread

I agree with this as well. I found it unrealistic that while i tried to use as much cover as possible, raiders with poor equipment and not very high skills could hit me easily even when it seemed like i only peeked out enough to shoot at them. i tweaked some settings on how skills affected spread and ended up with values that felt realistic to me.

I smell a mod coming along.

Let's see who gets it done first. Shame I'm at work for another hour and a half

That's right, it was part of a mod i used in F3. I don't think there has changed much in regard to the game's mechanics.

Actually, i wouldnt mind a reduction in accuracy as hole, for player and NPC... TBH i feel way too accurate (like, pinpoint accurate) when i'm manually aiming. I know the bullet goes where the gun is pointed, but the sway is so so so negligible... I'd like to see that augmented abit.