Scubakid,
I left out the answer to your other question...yes, you could keep a croucher in an 8 gal nano. It might be interesting to give it a branchy coral skeleton as the "centerpiece" decoration and see if the fish will take to it. Ours preferred the rockwork tho.
FWIW, I've been keeping venomous fish for over 20 years, and have never been stung. It's all about respecting the fish and knowing where they are if your hand is in the tank, altho in some of our setups, there are venomous fish "everywhere"...fortunately, they're all pretty tame and don't get spooked easily.
Just be careful, and know what to do is you get popped (excerpt from our scorp care article):
First aid for a scorpionfish sting is immersion of the affected area in hot water (114°F) for 20 up to 90 minutes, or until the pain subsides, in order to inactivate the thermolabile components of the venom. The reason for applying heat to the wound is because some scorpionfish venom is composed of heat labile proteins, and the heat actually denatures the venom. Please, don't use scalding-hot water, as the resulting burn will likely do more damage than the venom. To ensure the proper temperature have a cooking thermometer on hand.
Don't worry, unless you happen to be allergic to the venom, or you get stung by a stonefish, your life really isn't in danger from the effects of the venom. That being said, you need to guard against secondary infection of the wound as well as make certain that there are no pieces of the spine left in the wound, which can cause infection. A tetanus booster is recommended if it is past due. To that end, you may want to seek professional medical assistance, just in case.
HTH