Dirk, I just did all 4 shocks on a 2000 'S' with 54k miles. The shocks that came out were like new in the front and barely warn in the back. I did it for fun and to firm the car up a little. I put Bilstein HD on front and Bilstein Sport on the rear. I'm taking it in for alignment Wed.
I learned a whole bunch of things along the way. I used Wayne's method on the front with a twist I made up so I wouldn't have to loosen the main bolt holding the wishbone to the frame (not an easy bolt to get at). On the rear I followed these instructions
http://gwl.rmsolo.org/hacks/suspension/index.html (they include the front but it isn't necessary to do all that). The rear are a lot of work.
- You may or may not actually need shocks. Are the roads real bumpy? Your issues maybe unrelated. It can't hurt to change the shocks though. Shop around though i got mine for very cheap.
- Doing the outer tie rods is simple and inexpensive and certainly can't hurt. Mine were fine.
- You can very easily take out a sway bar bushing and check it. Mine were fine so so I left them. Should be just 4 (2 front 2 rear). Again real cheap just to buy them and put them in.
- As for the inner tie rods, once you get the outer ball joint off the wheel hub you should be able to feel if the inner tie rod has play...heck you can check the ball joint on the outer also.
- Drop links, my fronts were like new...once you get them off you'll see, just check the play in the ball joints. My rears were a little more tired but still no play, just more free. They are cheap and easy to replace though.
- Shock mounts...It would be really surprised if they are worn out. Mine were like new. I did buy new bearings just in case and used them but the old ones were just fine. You can have my old ones if you want them...if they fit. It is possible for a shock mount to get loose. Pretty easy to check that.
Since you are planning on replacing shocks you can test most ball joints along the way and if needed buy any control arms/wishbones/tie rods that have warn joints.
I'm not an expert but I would think your driving conditions, weather conditions, and any number of factors will play a big roll in how much you should do or need.
Hopefully the problems you talk about will be isolated to just a couple simple things. If you have any detail questions about how my recent project went let me know. Good luck.