Congrats on your new puppy!!!
I am also a full time college student and I work full time during school as well- so we are kinda in the same boat. Charlie has an exercise pen he stays in when I am gone to class or work and he is also using the piddle pads. I had the same problem as you- when I would be gone for awhile, he would rip the pad to shreds.. which, as you know is super frustrating. I know you can buy pad holders that will keep these in place, which might be a good investment, however I havent tried that with Charlie. He is now 5 months and is starting to grow out of the shredding phase. When I got home, I didnt punish him for shredding them, but sometimes when I was home i would catch him tearing at the pads, and would say NO... so far this is working for him. To keep him occupied when Im gone, I leave a couple toys in the pen with him, and switch different ones in everytime I leave. Also, I hang toys over the top of the pen, or put toys in places he has to work to get, which he enjoys more than toys that are just laying in front of him.
Charlie was a BIG cord chewer. Whenever I caught him chewing on things (my finger, a cord, etc.) I said NO, and replaced whatever he was chewing on with one of his chew toys...
With all of this stuff, the learning takes time. Charlie will still start to chew on my hairbrush every now and then and i remind him that hes doing something wrong.
Also, to your last question, I let Charlie know right away that biting was not ok. When he would bite (or nip) i would say OW (very loud and overexaggerated
) and pull my hand or finger back to show him that it hurts. This worked for us, as did holding his mouth closed after he tried to bite and say NO!
Hope I helped a little! Goodluck with Dallas