Everywhere is a potential market and every country can import according to their best price and advantage, as demonstrated by your examples.
Whatever TransCanada does is their business decision and I'll not attempt to second guess them.
The US shouldn't need to be "poised". Allowing more freedom in the marketplace wouldn't have necessitated this "poised" situation.
Maybe. I recall Bill Clinton using much the same excuse when he was president about why drilling for oil wasn't necessary, that it would take toó long to get to the market. But of course doing nothing is always an option, and frequently the most risk free politically.