Good questions. I have been researching the same thing for my new setup. What I found was that the live rock and sand are where the bacteria that turn the ammonia to nitrites are growing. Therefore, they need to be there. I assume you have cured the rock, otherwise the dieoff will produce more ammonia plus make the tank look pretty nasty.
To get the correct dosage, test the water first to get the initial reading. Add 1 tablespoon of ammonia and test the water. Add another tablespoon and test again, repeating until you get to 4 ppm
reading for the test. It's a lot of testing but you wont overdose that way. Then follow normal cycling procedure, testing the water at least daily for ammo, 'trites and 'trates looking for spikes in the levels then dropping off to zero. As the ammo level falls, you may need to add more of you dont see the spikes like you expect. To check if the tank is fully cycled, dose with ammonia again and you should see the 'trites and 'trates jump up and then fall to zero within a couple of days.
I admit that I have never tried this although I plan to when I get my tank completed. If my info is wrong I am sure some of our friends here will correct it.
Good luck! I will be following this thread to see if my info is correct. I would be interested to know how much you ended up using initially.