Actually I think that when you find a commodity and look to where it's highest sold it is updated, you don't have to land there again to comfirm the price.
As for the trade runs, I take more than few variables in account. While Kishiro's most profitable route could be Plutonium to Pennsylvania it is the route where you can plan to lose 2-5 million in one way on piracy. So while some people can be masters of FLcompanion, that won't help them much unless they know the real situation out there.