No, see <R38-B>. The voltage regulator on the radio 12v supply works to a much lower voltage then the camera’s 5v supply, and will keep the radio from cutting out when you draw a lot of current (for example making a hard turn late in the match). When the radio loses power, it takes a while for everything to link back up, and there’s nothing worse then having a robot dead on the field for 30 seconds.
If it’s used as a signal filter for a motor, yes, see <R63>. If it’s used in a custom circuit, no. However, inspectors would look very closely at something like a 1 farad capacitor to make sure it doesn’t violate <R03>, <R43>, <R62>, <R01>, <R02>, <R86>, and <R87> and probably a few others.
no, the radio can only be connected to the dedicated 12V connection through the Converter provided in the KOP(per rule R38.B)
<R38.B> The radio power feed must be connected via the 5V converter (model # TBJ12DK025Z) to the marked 12 Vdc supply terminals located at the end of the PD Board (i.e. the terminals located between the indicator LEDs, and not the main WAGO connectors along the sides of the PD Board). No other electrical load can be connected to these terminals (please see the 2011 Robot Power Distribution Diagram posted online at www.usfirst.org/frc/kitofparts for wiring information).
I don’t know about the capacitors, I haven’t seen a rule limiting their use.
If I remember correctly, the DS is always communicating with the robot(even during autonomous), however, rules disallow driver input during this time period, such as touching joysticks