whos only job is to grab the from the UDP packet
Grab the what?
int packetSize = Udp.parsePacket();
if(packetSize)
packetSize isn't a boolean. Don't use it like one.
Serial.print((int)Udp.read());
Serial.print(",");
//Serial.write((byte)Udp.read()); THIS WILL PUT THE BYTE ONTO THE PELCO SERIAL WIRES, NOT USED IN THIS TEST
No, it won't. You've read a char from the packet, and sent it to the serial port;. Reading another byte, and writing it to the serial port will NOT get it to the camera!
but I'm having a heck of a time getting it out the other end intact.
You should probably start with getting the packet size printing correctly, first.
sock.SendTo(send_buffer, endPoint);
How is this supposed to know how big send_buffer is?