-I'm pretty sure the first one is false because Guru Gobind Singh Ji is known for his fighting and warrior skills in Sikhi but I'm not sure if that was by choice or because of the ongoing fight. I do know that the Gurus did not want to be involved in political conflicts
-The leadership was not hereditary because Guru Nanak Dev Ji did not choose one of his sons to become his successor but rather another humble man
-There have been conflicts between Hindus and Sikhs in India, one of the best examples is the 1984 Genocide against Sikhs because two Sikh bodyguards assasinated Indira Gandhi, sparking rage in many Hindus in India, mostly Delhi
Hope I helped!