thats good you have some mechanical aptitude, many 4runner owners & just people in general today dont. a few others things to mention or suggest:
> its not always the best approach to just "throw parts at it" & replace multiple things at once, you wont ever know what actually fixed the issue. i would inspect & test the steering & suspension parts before just replacing them, although at 200k+ miles most parts may need replaced anyways.
>you ordered a bunch of brake parts but i dont see the most common failed brake part, the calipers. 4th gen calipers are notorious for sticking pistons & that will make the brakes drag & if the rotors are warped at all it will exaggerate a steering shimy or shake. lots of brake dust on teh wheels will be a sign of a frozen caliper, or use a temp gauge & check each rotor after a 10-15 minute highway drive & very little braking to see if any are extra hot, they should be almost cool to the touch after a brief drive & no braking. or jack it up & feel if any rotors are hard to turn, they should spin almost freely.
> check the steering rack itself, have a friend turn the wheel while you are under the car & see if the rack has excessive play around teh mount bushings or any other part of it... or the tierods etc. might have worn rack bushings.
> 4th gens also can have issues with the steering shaft itself, the joint can get rusted & stick or be worn a lot & have slop in it. check that joint under the car while youre checking other parts turning the wheel.
> & finally, even though you had the tires balanced, if alll the other checks & new parts fail to fix it, look into whats called road force balancing, its more expensive but they put a force on the tire to mimic the road & balance it that way, some say it helps a lot.
best of luck figuring it out. & please report back what you find, lots of guys post these threads & never report back after its fixed.