On the short drive back to the laundromat where I left my wife, completely out of her element, it does drive much better. Not perfect, still a slight pull to passenger side when applying power.
Idk if it’s bushing or if a perfect alignment isn’t possible given the weight, build, and use case of my cruiser. It’s also completely possible that this is how it drove when I got it new after all the modifications and I have forgotten. What I do know is that once the alignment went out the first time I’ve been chasing the dragon ever since.
How would I best test this bushing theory?
It's hard to test bushings without pulling arms to directly examine. With bushings, it's really more a degree of wear. And how much compliance is normal versus too much.
The pull on throttle is likely normal to your setup because of lift. Remind me, how much lift do you have?
With lift, the panhard is at a steeper angle displacing the axle to the driver a bit. This also causes a thrust angle. If you look at your rear alignment, it shows a thrust angle of .53 which means that the whole axle is pointed to the passenger side slightly. In straight ahead driving, it's always crabbing to the passenger to some degree.
When accelerating, the rear will squat slightly, reducing the thrust angle, and this minor rear steer causes you to feel some pull to the driver.
If you're lifted 2-3", I would recommend a panhard correction kit (PCK) to fix the rear thrust angle and rear steer. Using an adjustable panhard is not the solution so many reach for because it's less about axle displacement than it is the sagitta of the panhard causing thrust angle to change when the rear axle height changes due to load/accel/decel/bumps.