Yes they do, they have nocturnal sweeper tentacles that will sting nearby corals and possibly octo skin
Nessen, the small octopus to begin with will live in holes in the live rock but once it gets a bit bigger they have been known to try their arms at DIY. They may reaarange the rocks and anything on the rocks to whereever they want it. As they grow you may need to remove some rocks to make space.
sounds like a fun project