The diffs are already shimmed out of the box. Each side has 2 0.2mm shims. The pinion has 1 0.2mm shim. Very little play.

Nope, no grease in the tranny.

The switch is mounted to the ESC plate. It is completely sealed with a flexible hood. It's the white square in the last picture behind the three motor leads.

Weight is 11 pounds 6 ounces. I already bought an extra bulkhead and R&P set just in case. The HPI website has them in stock.