Tank is looking good!
Mounting everything to the rocks is always a good idea, it's usually best if you can get the coral off the plug and mount directly to the rock. I have had tanks in which I have drilled holes for the frag plugs, including some rock in my current tank. I don't see anything in there that would justify such a big project.
You'll want to be careful with that green star polyp. It will overrun that entire rock. Those zoas will most likely grow out pretty fast as well and cover the other side of the rock. I see you having to move the blastos down or somewhere away.
The chalice will most likely cover that top rock, watch out for it's long sweeper tentacles that come out from it's eyes at night, they are known to sting corals placed inches away!