Welcome to the sad reality of the aftermarket parts. However now you're initiated. Congratulations! LOL
I bought a kit in 1989 from a company called "Mr Suspension" and the tie rod ends weren't crimped down right - grease pumped out all along the edges. Another Sat trip to 002 autoparts. At least then and there, it was pretty easy to buy good stuff locally, and it was often in stock. But the kits that seemed like a deal, and the just replace it all, yea. I got initiated too. ;)
To your question. Although the non-machined surface would probably work, its not good practice. Threaded fasteners hold by the tension in the threads. More precisely, the steel stretches or distorts, but not so much that it takes a permanent set. If there is soft material or gaps between the clamped parts, movement from vibration or impact or load is very possible. The movement will allow that tension in the threads to relax, and then back out. The movement may also allow wear on the bolt shoulder.
One way to chase part numbers is look up the OEM Chrysler number first. That's the better way to chase cross references, especially when manufactures decide to cross list parts they deem are close enough to be functional. Sometimes they really are, but sometimes they physically fit, but don't actual function the same (like different length arms).
Lower Ball joints are allowed some vertical movement with the weight off the wheel. The shop manual will have the details of how much is allowable. The movement is taken up when the weights on the wheel. Your old NAPA ones may be OK.
Steering play. There's often a little play in the box when the car isn't moving and wheels are straight. That said..
First - check the wheel bearings aren't loose. If there is in/out movement when you hold the wheel top and bottome (12 and 6), that's number one to tighten to specs.
Second - With one wheel on the ground move the one off the ground as the steering wheel would. Watch each link and joint in the steering linkage until you see the movement.
Then do it from the other side. Get a helper if you need. I prefer to do it myself even though it was awkward because I can feel the movement if there is any and match it with what I'm seeing.
A front sway bar is good move for any driver. You'll notice the better control even with basic all season radials.