How important is New Orleans to the US economy, really?

Factual Questions
1

One of the many arguments roiling over the recent disaster (some of which I’m more comfortable with than others) is not only how, but whether to rebuild New Orleans.

Many folks have claimed that the city is vital to the rest of the country, through its role at the mouth of the Mississippi. How true is this? I know gas prices are rising, but isn’t that due to factors other than the city itself (ie the refineries and pipelines, which either could be anywhere or are not dependent on the rest of the city)? If New Orleans were totally abandoned, how would that affect the rest of the country, if at all? If it were rebuilt at a “safer” point?

2

Others know more, but all the surrounding Gulf Coast ports are going to have to take over all that traffic.

And then there’s that whole Mississippi River thing…
Barges coming down the river have to come out somewhere.

3

Here’s a Miami Herald Overview of New Orleans and the Gulf ports.
An example:

4

Actually, there’s been serious talk about routing some of it all the way up the eastern seaboard, through the St. Lawrance, and to the Indiana and Illinois ports on the Great Lakes, which would give access to the Mississippi from the north.

5

Currently, there are some 90 vessels awaiting entry into the port of New Orleans.

6

Another problem with diverting the vessels to another port is that you will also need more people at the other ports to help unload all the stuff. L.A. and Long Beach have had a lot of ships come in, but they have had manpower shortages to get the stuff off. So it’s not all very useful if it’s still in the container ship.