[vhcook]

3- Are you wanting to put speakers on your robot cart? If so, that's not allowed per section 3.3.6 and 3.9.12: "Do not add music to the cart". The reasoning behind this (as I understand it) is that it's distracting and can interfere with people's ability to hear announcements. Within your pit, any sound system would need to be kept at a very low volume that doesn't interfere with the ability of your neighbors to hear queueing announcements (see section 3.17).

As far as what frequencies, if any, would be ok to use in the pit, since these aren't the forbidden two-way radios, I'd check with the event staff at your regional in advance. In addition to the robot-control signaling, there's a lot of other stuff going on behind the scenes, and some of it is going to vary between regionals.