Re: buying first set up, questions
I fucking hate my Comet (sorry for swearing but I had to illustrate how much I hate it), I will never go near a rotator ever again! But if you can get it working well enough by all means get it. However I definitely think you should do more research, there are cheaper and better hookahs out there. You are in the right place to ask questions and learn more about everything, read hookah reviews and do that testing thing at the hookah bar its a good idea. Good luck in finding your first hookah.
PS: Everything else on that list looks really good.