There's a part number for a stud to mount a steering stabilizer, so I imagine some of them came with one. I added one to mine, but, yeah, I can't really tell it's there. To be fair, I used the cheapest stabilizer I could find (>$20 IIRC, probably some Monroe crap), so your mileage may vary with a better unit. I'm also running a Grassroots centerlink, which has enough drag to do a fair bit of stabilizing on its own.
The clunk and the pull are likely related. +1 for checking the UCAs. The camber and caster are adjusted with U-shaped shims, and if the bolts back out, the shims fall out, and then your alignment goes full stance nation.
The squeal while turning is interesting. I doubt it's the pump--it shouldn't be able to tell which way you're turning. Might be a blocked passage or something in the box, but I haven't heard of one doing that, and it wouldn't explain why it only makes noise when you're moving. Maybe one of the wheel bearings is loose enough that the rotor is hitting the backing plate? Again, could be a shared cause with the clunk and the pull, depending on what's rubbing on what. Add bearings and brakes to your inspection list if they weren't there already.
If nothing jumps out at you when you inspect the front end, run it without the power steering belt and see if the noise goes away. That should rule the hydraulic components in or out.