England's General Teaching Council conduct committee heard that Roselyn Donovan, who worked at Heathmere primary, in Roehampton, west London, drove one member of staff to have a nervous breakdown and mismanaged the school's finances.
Mrs Donovan also failed to report a child displaying overtly sexual behaviour in class, another pupil expressing fear about his mother's boyfriend, and a third having access to weight-loss pills at home, the committee heard.
Karen Cork, the presenting officer, said: "She placed the school, the reputation of the teaching profession and the well-being of children at considerable risk. She has shown no remorse, regret or insight into her conduct and has offered no explanation."
Glenys Lawrence, who was head of contracts and personnel for Wandsworth local authority, investigated Mrs Donovan's conduct after complaints from the deputy head in 2004. She said: "She was confrontational, aggressive and unprofessional."
She told the panel that Mrs Donovan would frequently leave school during the day to go to the gym or meet friends, without telling anyone or placing anyone else in charge. "Vacant posts were not advertised, junior staff were promoted to senior roles and her overall strategy was to avoid responsibility," she said.
Angela Stones, the chair of the committee, said: "Mrs Donovan seriously disadvantaged colleagues and jeopardised the finances of the school. She abused the trust that pupils, parents, colleagues and governors were entitled to place in her, and the well-being of vulnerable pupils was put at risk."
Mrs Donovan was not present and was not represented.