For your first question, the Red wire (Pin#2) is for power. The answer to your question would be Yes.
Regarding your second inquiry, you will possibly need an external 5 volt power supply. Perhaps, a 12V DC to 5V DC converter.
We have not personally tested the BR-355 with the VHF Radio. The pinout diagram that was provided is for reference.
However, we have one customer that was able to make it work with the MR-350 (another Serial GPS Receiver).
Basically, he picked up a PS2 extension cable at a Radio Shack store. Then, he cut it open because he did not want to muck up the the MR-350 cable. He plugged in the unit to the USB port of his computer. The power that goes through the device is coming from the computer as it needs a power source. Afterwards, he connected the MR-350's RX to the Marine Radio VHF Input(+) and Ground to VHF Input(-). Afterwards, it gave him the GPS Position Info to the VHF for the DSC function to work.
As for the VHF NMEA Outputs, these pins can only be used with a compatible chartplotter.