[What is this material ?]

If it's a full size (human size) built in 1 piece then most likely it's PC-ABS from Stratasys (it only comes in black ) or Ultem 9085 (PEI/PC) which come in natural tan or black.

[Best filament for a specific project]

I agree with Labern to use co-polyester (CPE). I would build on edge to have the layers go perpendicular to the stress on the snap-fits. I disagree with glue as this creates an inherent weakness.

[3DXTech 3DXSTAT ESD-PC]

Anyone have a cheat sheet for settings and parameters or any experience with this material?  I am using it for an industrial application and can't seem to get it to quit curling or not sticking to the platform.  Not a fan of air builds.

[Filament being ground down on new UM3]

This is a spin-out of the filament in the drive due to a block in the print core. I would suggest raising the temperature of the print core and try pushing the filament either manually or loading in a cleaning filament and letting it purge. If this doesn't work you'll have to clean the print core manually or swap print cores. Once the print core is clear, then snip off the filament that has already gone through the drive and re-load and purge. Make sure your temperature settings are correct for the filament. I had this happen to me right out of the box and this is what I did to correct it. I have 14 years of experience in working with FDM machines professionally.