If the tank has not cycled yet, it may have that ammonia spike now if the live rock has die off....check that. Die off on the live rock is good, it will help the cycle.
While the tank cycles, you don't need a skimmer, purigen, carbon...nothing. Run the power heads and regular filters. Do tests to see where you are at in the cycle. I haven't read the entire thread, you should have your own test kits.
You don't rinse live sand, don't do a water change either. Turn off the pumps and filters, add the sand and wait for it to clear....then turn back on the filters and pumps.
You are asking the right questions but you are way ahead of yourself. Things will clear up as you go....you won't need a skimmer for another 2 to 4 months depending on how much you stock.