These can be translated as:
1) 내가 아는 바로는 - 'To my knowledge' or 'As I know'
2) 내가 아는 한 - 'As far as I know'
3) 내가 아는 바에 의하면 - 'According to my knowledge'
Yes, they are commonly used. Maybe in written form.
I guess I normally just say '내가 알기론, 내가 알기로는' in casual conversation.