I agree with jello below. A basic one ester test cycle like Test E and NO orals or any other compounds would be ideal for this situation. But IF you plan on running this anyways whether it be because you already have the gear and don't want to feel like you wasted your money or whatever it may be, I will try to answer a couple of your questions because some help is better than no help just because I don't agree with you running the cycle right off the RIP doesn't mean it's helpful to not give some feedback. I would rather see you do a cycle I don't agree with correctly then see you do a cycle I don't agree with incorrectly. So....
question 1: yes it is necessary to leave such a gap in between your last pin and PCT. Sustanon has the longest test tester in the DEC. Ester. this Ester is even longer than Enanthate or cypionate. in 2 weeks is the recommended protocol for those ones. Let alone the DEC. ester.
question 2: Sustanon usually kicks in pretty fast and pretty 500mg isn't a hell of a lot, I still don't like to wait until I get to the point where I am having estro symptoms because that means it is already way over the limit and sometimes hard to control after that without knowing your body yet. if I were you, and I am NOT saying to absolutely do this mind you, but if I were in your position I would take .5mg of adex every 3 days and if you start feeling symptoms of low estrogen levels then back it off. If you start feeling symptoms of high estrogen then dial it in better. but because of the short esters involved I personaly usually would start no more than one week after my first pin. With me usually day four.
question 3: I can't go into question 3 because I don't know enough about TRT and cruising.
question 4: if your body fat isn't already in single digits or damn near then no anavar would not be a better substitute because you wouldnt tell much of a difference anyways. Not for cutting wise anyways. For strength wise you will be fine with the tbol.