If we're using the user_analog[6:4] pins, do we need to do anything with the corresponding clamp pins, i.e. tie them low or high or leave them open?

On our first test chip we (accidentally) left the clamps unconnected and the chip worked, so it seems to be okay, but I would still recommend grounding both clamp pins.

@Tim Edwards if you want to use ESD protection on those pads is the idea that you tie both the hi and low clamps and both core nets together? I.e. tie all four metal stubs together?