Which is the Safest driving-(keep left with right/left hand drive)-(keep right with right/left hand drive)?

Any of those configurations could be equally safe as long as it is consistent. The main problem is when drivers used to one way have to adapt to another. It is extremely difficult at first. It would be nice if there were a global standard. Unfortunately, with India, the UK, and Japan on the left, and most of the other largest countries on the right, this isn't going away. I actually had to drive on the left in St. John, which is supposed to be a US territory.