(1) Don't lick the bullets for flavor, maybe think about wearing some nitrile gloves while reloading, limit indoor range use, and wash your hands with cold water after shooting. Dose makes poison. Most of the people with adverse health conditions from lead exposure spent a lot of time in lead-soaked environments--professional rangemasters, for instance.

(2) If you want cheaper .500 Mags, cast lead is the way to go. But really, .500 is expensive to shoot, and there's no getting around that.

(3) I would suggest that focusing on crimp tightness ignores the other half of the equation--where the crimp is. If you start the crimp with the case mouth all the way at the top of the groove, the crimp is formed with an enormous empty space beneath it, allowing for bullet jump. Not that I'm actually convinced you have a bullet jump problem.

(4) I highly doubt that you have any sort of an issue with the primers. My .44s loaded with WLPs get a fairly "dished" look to them after firing, with everything from moderate to maximum loads. Protip: nobody blows more hot air than an old fart who hangs out at the range for free to minimum wage. These are the guys that couldn't get a job working at the gun shop for an at-cost gun a month.