I wouldn't feed any fish chicken meat but then again they are your fish. just feed NLS exclusively and you can't go wrong.
I think its fine. Lots of people (unwisely) feed Gars and other big carnivors hot dogs. I think chicken is a lot better than hot dogs....
Like others said, it shouldn't be a staple, but if you have some extra, its probably fine.
Most poultry contains harmful bacteria (Consumer Reports found that 97% of the 300 chicken samples they tested from around the US had dangerous bacteria), of which salmonella is one of the most common. Salmonella survives in water, so it's not really a good idea to put raw poultry in your fish tank.
Cooking the poultry all the way through to 165F can kill salmonella, but likely makes the food unpalatable.
Of course a lot of animals will eat anything when hungry: dogs will eat chocolate, kids will eat cotton candy and ice cream, adults will eat lard, etc. For fish, the worse that happens is that it shortens the life span of your pet. If it's guppies or mollies, I don't care.
If my "should have lived to be" 16 year-old pacu dies at 10 years old, I think I'm going to care. However, even if all food is on the menu, I'd still recommend pet owners skip feeding raw poultry, as the risks from a human infection simply are too high.