Discus spitting out food is a pretty sure sign of internal parasites. The shape that your discus are in, it would be hard to believe they don't have parasites, just very, very common when purchasing discus from LFS. Right now the next step I would take would be to treat them for internal parasites with Metronidazole (Metro) which treats internal flagellates, the most common internal ailment in discus.
Some amount of bullying amongst discus juvies is normal. It's part of them growing up. Every once in a while you get a real tyrant of a discus that barely lets anyone on the tank move.....I have had them and rehomed them. The bigger the discus group, the more spread out the aggression is so that one particular fish isn't getting picked on all the time. If one discus gets singled out and bullied relentlessly, they often stress themselves to death.