disc conversion then alignment no good

Well those front wheels are not helping either at 1.75 backspace, you have moved the tire center to the outside of the factory designed scrub radiusd;the wrong way. The factory wheels have a near zero offset. Yours are .75 offset to the outboard side,and your tires are about 1 inch taller than factory, moving the contact point at the roadway even more outboard. Now I don't know which way the 73up spindles push the scrub radius but I'm pretty sure it's also outboard. So all in all, this scrub radius thing may/will cause the wheels to want to self-steer. This may not be helping the near-crappy (being kind here) alignment.Perhaps it's the best your guy could do with the parts installed, so don't jump on him right away. Give him a chance to explain.
The skosh chart is very helpful.

PS; you don't have air shocks on the back, do you?