Thank you, Kennyfvholla.
The bearings (12 and 6) feel solid. The tie rods (3 and 9) have a little play. I've seen much much worse though.
Every wheel and tire SHOULD be balanced, and alignement SHOULD be good. If it comes down to it I can have another shop check their work. But like I said, its intermittant. At least half the time it feels properly aligned.
I hadn't thought of your tests for the rack and for the cv joint. Will try those today.
The CV joint makes the most sense to me, considering that the movement is based on wheel rotations under power. Any further ways to test this before replacing it?