Reading RoboClaw using packet serial, but can I use pins D0 and D1?

I'm using the Ethernet Pro (based on the Arduino Uno) and I'm using the RoboClaw motor controller and communicating with it using packet serial.

Since digital pins D0 and D1 are meant for serial communication (from what I understand), even though the logic pins for the RoboClaw are on D5, D6, would I still be able to use D0 and D1 as digital I/O pins?

For example:

#include "BMSerial.h"
#include "RoboClaw.h"

#define address 0x80

RoboClaw roboclaw(5,6);

void setup() {
  roboclaw.begin(2400);
}

void loop() {
  roboclaw.ForwardM1(address,64); //start Motor1 forward at half speed
  roboclaw.BackwardM2(address,64); //start Motor2 backward at half speed
  delay(2000);
  roboclaw.BackwardM1(address,64);
  roboclaw.ForwardM2(address,64);
  delay(2000);
  roboclaw.ForwardBackwardM1(address,96); //start Motor1 forward at half speed
  roboclaw.ForwardBackwardM2(address,32); //start Motor2 backward at half speed
  delay(2000);
  roboclaw.ForwardBackwardM1(address,32);
  roboclaw.ForwardBackwardM2(address,96);
  delay(2000);
}

Would tacking in pinMode(0,INPUT) give me an error?

It won't give an error as such. Why do you want to? Your sketch doesn't seem to indicate you are running out of pins.

I will be using most of my pins for a bunch of simple buttons for simplicity.