That rock is gorgeous. Sad to think that a lot of it will die off. If I ever get really nice rock, I usually separate it from the rest and treat it very nicely, using ammo carb, refreshing every day or two, and doing large water changes on a daily basis, sometimes even placing an established biofilter on there, cured live rock or an established canister filter. A good portion of that rock falls into that category, IMO. The thing on water changes now, though, is if whats in there has already been through a week of 5 ppm NH3, whatever's not dead isn't going to be seriously harmed by 3-4 ppm of NO2. If you haven't been doing water changes from day one to prevent major die-off when most of it is happening due to NH3 exposure, there's not much of a point to starting once the cycle is half done. You should do a water change before you add additional livestock, but I don't see a big reason for it right now. Sounds like the last of the major NO2 addition to the water has already occurred, and now you're just adding to the bacteria population to get it down to zero. Water changes won't starve the bacteria, like IslandCrow said, but a disruption in the water consistency (if your salinity, temp, pH, or alk are off) can cause small die-offs in the bacteria population. Don't wait too long after the NO2 disappears to add a small cleanup crew. 2 weeks is an okay recommendation, but i'd add a couple little critters 5-7 days after you start to see stability, or the bacteria will begin to starve. The rock will continue to produce minimal amounts of NH3 and in turn NO2, but not enough to sustain the large bacteria population that you will have established by this time next week. Just my .02.
Nice looking stuff, and its pretty well arranged within the tank. Keep us posted on progress.