The SPS pieces won't be a problem for an octopus, but I would worry that it would knock them over or pull them around and tear them up. Doesn't take any effort at all to snap montipora into pieces. I see some "trumpet/candy cane" corals and euphyllia of sorts and those would burn the octos skin.
Cuttle might do just fine with those corals, but I wouldn't swear on it. Those LPS can and do occasionally have some sweeper tentacles extend out into the water column.