All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad is His slave and Messenger.
Al-Munaawi said in his book Faydhul-Qadeer while listing the virtues of Abu Bakr "Abu Bakr, his father, his son, and his grandchildren embraced Islam. He never prostrated to an idol nor drank wine."
As for the second part of the question, we have not found in any of our references that Abu Bakr threw a stone at the idol. For further information about the virtues of Abu Bakr see Fatwas ">86517 and 90882.
Allaah Knows best.