Most of the major shipping routes should be replaced with rail, which is (a) faster, and (b) can be electrified much more easily. It's also just plain more energy-efficient -- rolling is better than trying to fight the waves.
The major problems with this are political, not technological. Even the Bering Strait route is pretty straightforward technically.
I guess Australia would still need ships though.
Hmmm not sure I agree with some of your statements. I agree with the last one, though.
Link to Shipping Comparisons, compares different transportation modes on cargo capacity, safety, energy efficiency and environmental emissions.
Train comes on top only in cargo carrying capacity
Ships win on energy efficiency and all other metrics