once more, KidTako.
Bluering octopus are deadly poisonous, so may well survive their keeper, although I would not put that down to hardiness... Stonefish can be lethal also and will swallow anything the size of their mouth that happens to swim/stroll past, such as a small octopus. Normally, a post like this would therefore be considered as eminating from the mysterious mountain forests of Norway, but I will gladly give you the benefit of the doubt
So, no, the keeping of bluering octopus outside of a research environment is strongly discouraged and not the material for "oh yeah?! I'll show you rebellion!" excercises; people do die of bluering bites, seriously. Keeping a small octopus or cuttlefish with a midsize predatory fish is generally a bad, bad idea, unless Stonefish would have some innate knowledge of what species not to touch, not even with a ten foot lure... I know some predators do under some circumstances, but I'll refrain from commenting in this case.
To refine my response; octopus keeping can be very rewarding, if you limit yourself to diurnal species of smaller size.
Big species such as O. vulgaris or GPO will challenge most non-professional tank keepers to beyond their capacities. Bimacs are very social and often available through the trade. It is best to keep the octopus solitary, as it is its preferred state in the wild, also. Bar prey items, of course, that it readily welcomes into its den for a "special tea"
Edit: finding a stonefish to keep (solitary) in a tank is a daunting task. A number of dealers/LFS's will tell you they can get them, but you usually end up with a scorpionfish of sorts, hardly ever
S. verrucosa or
S. horrida.