LOL, the skunk stripe is seen on all octos so you can't use it for ID but the rest holds. If you have more mollies in the tank, please remove them. Fish in general are a bad idea on several levels but freshwater fish are particularly bad as all (or at least most) have been treated with copper for parasites. Copper is lethal and we have lost at least one octo from eating gold fish.
Your easiest dead food will be regular seafood counter or frozen shrimp (start by offering with shell on and then remove the shell once Waldo accepts it easily (you can buy shell off once they accept it that way but we find the shrimp seem to be less dried out if purchased shell on). They don't eat the shell but we have noticed that young octos seem to take shell on shrimp easier - be sure to clean up the discards ASAP to keep your nitrates in check). Be sure to thaw anything frozen for at least 15 minutes in tank or new saltwater. Second on the list and our personal number one choice is blue crab claw but you cannot find uncooked crab frozen. We go to the Asian market and paw through the fresh crab bins for loose claws (start by separating the claw and arm, feeding each separately as a meal the full claw and arm will be too much food). These CAN be frozen safely and are excellent food. You can feed any part of a fresh uncooked crab but don't freeze anything but the claws. If you can find live clams, these will sometimes be eaten but they do well in aquariums and can be a minor clean up crew until consumed. I put them in a bucket of tank water (make it fairly deep as they will drain something shallow and leave your counter wet with their spitting) over night to eliminate the water they have been kept in while out of the ocean and to be sure they will survive. Check them from time to time to be sure that they are alive but they don't pollute much. You can also offer mussels and oysters but these are heavy polluters and any uneaten remains are hard to remove and messy. Scallops are a healthy choice, however, IME, they will eat exactly one thawed scallop and no more so don't load up on them. You can offer pieces of raw saltwater fish from the market (again, avoid pet store fish). Any kind of small live crab is acceptable and fiddlers are a universal favorite. They are expensive in the pet stores but much more reasonable purchased on-line (
Paul Sachs is an excellent supplier, used by many TONMOers).
Freshwater animals are not recommended but you can give an occasional treat of crawfish. Here again you cannot freeze the body but can freeze the tails and claws if you remove them from a fresh animal. The whole live animal can be offered but be sure it is eaten and remove it immediately if ignored and it dies in the tank (roughly an hour or less). As I mentioned above, avoid feeding any kind of pet store fish because of the copper treatments.
You can keep hermits and snails for your clean up crew. In most cases (there are exceptions but not likely with this one) once they are accustomed to being fed, they will leave the hermits and snails alone but these are also acceptable food in a pinch if the octo will eat them.
There are differing opinions on the use of blue LED lighting (ie moon lights but NOT actinic any PC is too bright for a nocturnal regardless of lowered wattage). I use red because it is almost invisible to the octos (in fact my young ones usually den directly under the red but often migrate to darker areas when they become adults). Blue may appear as bright as white light and keep your octo in hiding, however, some people have reported success with normal moon lights. IMO, go with the red, it is not expensive (albeit not attractive) and easily set up with a little thought. I've kept two fully nocturnal species (the Macropuses and O. mercatoris) and usually have a resident O. briareus that is crepuscular as an adult (early evening early morning hunter) but nocturnal as a juvenile and believe the red does provides more viewing (lousy photography though). The cheap, ugly light is easily removed for a diurnal species (who need total darkness at night IME) and can be upgraded to something more attractive if you continue to keep nocturnals. Keep in mind that the life span is very short (a year or less) and you are not starting out with a hatchling so make the best of your time with Waldo (size wise I think you may have lucked out on a fairly young one but size is not a consistent factor of age).
With your permission, I would like to move Waldo to our journal area in hopes that you will continue to log your experience.