Is it safe to say that this is your first saltwater aquarium? If so, congratulation, I think you will enjoy it. The type of setup you have chosen is unconventional, but actually rather easy to care for.
I think you are on the right track by choosing to use live rock as the primary life support system on this tank. I agree with the given advise that you should add the live rock now, and then wait for the tank to cycle. You will want somewhere in the neighborhood of 8 to 15 pounds of live rock to begin with, erring on the upper side because of your choice in substrate. Had you used a reef grade aragonite sand, you may have saved some money by having less rock. Unfortunately crushed coral provides very little benefits in a marine aquarium because of the size of the individual coral pieces.
I also agree to remove the air stones, which will cause the tank to be much more difficult to care for. They cause salt creep and fluctuating salinity levels, and provide almost no benefits. The water pumps are plenty for circulation.
I do think your long term goal is attainable, provided you purchase Ocellaris Clownfish, hopefully tank raised. They do good in pairs, stay reasonably small, and are hardy when purchased TANK RAISED.
After you get the rock in place within a week or so you will see the ammonia and nitrite go away. I would strongly suggest you wait a minimum of 4 to 6 weeks on a small tank before adding fish. You could add a snail or small hermit crab, but otherwise just let the tank mature. I would continue with 2 gallon weekly water changes at this time.
For the record, I would not worry about testing for alkalinity weekly on this tank, given the weekly water changes. A monthly test should be sufficient, targeting 10 to 12 DKH.