I dk man, shut down is shut down and I would think that 12 weeks of test at 500mgs/week is plenty to shut the body down. I would definitely use HCG on cycle, but that is completely up to you. Apparantely many don't use it, so that's your call. If you decide to run it, you inject 250iu twice a week. You start injecting HCG on the 3rd week and continue it till your last test injection.
I start running my AI during the 3rd week and I run it all the way through my cycle and into my PCT to keep e2 rebound down. It has worked well for me and I have had no gyno signs. Run your DAA during PCT only.
Everyone has there own methods and theories. Do what we have done and find out what works for you and what doesn't. The first cycle can be nerve racking with all the advice being thrown at you. Have faith in yourself, do the pins correctly, run an AI, end with a SERM in your PCT, and you'll come out just fine!