J,
1. The standard does not require LOTO procedures for cord and plug electric equipment. See 1910.147(a)(2)(iii).
2. As long as the procedure is accessible to the employee you're fine. However, I like to have the procedure with the equipment. It cuts down on the "I forgot" events.
3. Yes, but your procedure can state that you'll fall under the contractor's procedure for that particular task. See 1910.147(f)(2). Generally, work with contractors requires informing each other of the other procedures.
4. I'm not sure whether the Appendix is mandatory or non-mandatoy. You probably could get away with just titles or use the broad based "Area management and employees will be informed." I prefer the use signs, barrier tapes, and announcements. That way any affected or other personnel in the area or entering the area is automatically informed.
The good news is that if you do it thoroughly and correctly on the front end, the annual periodic reviews and procedure updates become a breeze.
MikeCJ