Should I feed a young Oscar pinkies?

Feed your Oscar fingers? Ewwww. Oh, I guess you mean pinkie (newborn) mice. A large Oscar could, and probably would, eat pinkie mice, but it's not a good diet for an Oscar. Fish are not good at digesting the proteins and fats found in mammals. Mice are not my field, so I don't know at what age they get teeth and claws, but injuries to your fish might also be a hazard. Cruelty to the mouse is another issue, but I'll let others debate that. Most fish food is made of some kind of animals (with or without other ingredients), so what it's ethical to feed a carnivorous fish is not a black and white matter.

Yeah that would be fine, wouldn't hurt. Just don't do it too often. Maybe like once a month as a treat or something. As for the Oscar being young it's probably not big enough to swallow it yet.

no, pinkies are not proper nutrition, (especially for a young oscar) although occasionally wouldn't hurt anything, it will not only foul the tank more, but also lead to nutritional problems if done too much. oscars will however eat banana, apple, peaches, broccoli, peas, etc. along with high quality feeder fish like mollies, guppies, minnows, small cichlids like convicts, but not goldfish, these lead to disease and malformation (HLLE / HITH) , squid, shrimp, clam etc. Oscars are primarily vegetarian in the wild, and other fish, bugs and small animals make up a smaller part of a healthy diet. NOTE: in most tanks, feeding properly would foul the tank, ruin the water quality and increase the incidence of disease etc. This is why experienced aquariasts claim that really large tanks are required for Oscars, over 200 gallon, even though most people try to keep them in 55-75 gallon tanks and think it's fine...