Wow that is a lot of rock
If you decide to try drying out and re curing it is going to be a long road so set your mind to that....
Since you are planning to reduce the amount of rock anyway, Start with the rock pieces that you really like the shape of and can envision a cool looking reef structure when you put it back together.
And yes "cooking" live rock does not mean literally cooking it, do not boil it!
Dry it out, scrape and clean it, cure it in a Rubbermaid. A pump, heater, and dark. A week or two drying, a month or two curing.
Rock that you won't be reusing just dry out and save you may want it at a later time
Corals can be kept in display the whole time but imagine it more as a quarantine tank or frag tank for a while, not really a display. Maybe build yourself a rack out of egg crate that you can place corals on so you can easily inspect and care for them during the rock curing process.
With all that rock to choose from, and a little imagination, you could end up with an awesome aqua scape, clean of aptasia, but it will take time and commitment
a copperband butterfly could be added to your tank to help with the aptasia as well they are by far your best aptasia eater if you can find a healthy one that lives. This may be the only way to get the aptasia growing in and around your zoas, and other corals.
If you choose this route - good luck, and think long term