Eating after brushing teeth at night, bad hygiene?

Defeats the purpose. Good for you for brushing at night. However, not brushing after you eat will leave food and particles in your mouth overnight. Not the best idea.
Yes. If you eat after brushing and go to bed, sugars and acids begin to work on your teeth and bacteria overgrow. The who purpose of brushing is to remove these substances to give you optimum oral health. Try to avoid this practice. "grit your teeth and just do it. It's something you can sink your teeth into.".
Yes. Brushing and flossing should be the last thing done before getting in bed. Otherwise sugars and food will be on your teeth doing their damage while u sleep.