The rock will not be able to handle anything that you throw at it. This is simply not true. Even if you don't kill a fish, if you raise ammonia just a touch, you could lose a stony coral or some other sensitive invert on the rock that might have otherwise lived. You can also damage fish without killing them - think of asbestos exposure or mesothelioma for humans when exposed to toxic things with their lungs like fish can get in the early stages of a tank to their gills. You still have to wait for the ecosystem to develop. Since cycles are never done and are ongoing, there is also no such thing as an instant cycle - the idea is just ignorant and I am sorry that a few self-important individuals on this board like to say such things.
Bacteria for fish waste is only a smart part of a real cycle. It is only really ever needed in the beginning when there are no other things to use fish waste directly. These are AOB - ammonia oxidizing bacteria. As things grow and establish, coral, film algae and other bacterias start to use ammonia directly for the nitrogen and the bacteria that people add from a bottle and talk so much (the AOB) about die back quite a bit - they just are not needed as much anymore. They never fully disappear, but they become relegated to the sidelines and clean up with does not get used directly.
As your tank matures, with each cycle, more and more things grow on surfaces and in the water column and most of these are not AOB. If you remove a bunch of corals, then the next cycle the AOB will multiply since there are not as many corals there to use nh4 directly. Each cycle brings balance in time - nature will work it out if you do not interfere too much.
Cycling is a process. It is never over until your tank is shut down. Think that a cycle completes and that somehow something is done or a tank is static is just folly and does not help the hobby.
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