On presence of "idols" in "Golden temple" in Punjab: There were various idols of Sikh gurus at different places within the temple complex. There were idols of Hindu deities along with Pujaris for rituals.
There were idols of deities near the tank. A painting of Govind Singh receiving sword from the goddess.
In 1905, under increasing pressure from "reformist" Singh Sabha propaganda, the idols were removed and Brahmans prohibited to carry out rituals inside the temple.
Sources are "A World Reconstructed: Religion, Ritual and Community Among the Sikhs, 1850-1909" "Spatializing Popular Sufi Shrines in Punjab: Dreams, Memories, Territoriality"
