from the Oil and Gas Journal:

Cumulative production losses in the gulf through Aug. 31 following Katrina reached 6,055,220 bbl of oil, or 1.106% of the 547.5 million bbl yearly total, and 34.19 bcf of gas, or 0.937% of the 3.65 tcf yearly total, MMS said.

Offshore drilling contractors said that two jack up rigs were lost and four semisubmersibles broke free of their moorings in the high winds (see story elsewhere on OGJ Online). Crews were evacuated before the storm arrived, and flyovers afterward did not reveal major surface damage, the companies said in separate releases.

Near-shore and coastal producers said flyovers generally showed little damage to their operations, although flooding and damage in surrounding areas could affect restoration of full production. More detailed assessments will be conducted once employees return to the sites, they added. .....

While supply effects could be substantial, he cautioned that early dire predictions of retail price spikes and supply interruptions may not necessarily materialize. Cavaney cited the Louisiana Offshore Oil Port, where early reports suggested major damage but which now will be able to resume operations once electricity is restored.

as for your other questions, I really don't know that much.  My time in real engineering was mostly focused on refinery process design.  The little work I did for upstream units was on the West Coast.  The 2nd half of my career I traded oil products rather than crude so what I know is 2nd hand from the others sitting at my elbow (literally if you've ever seen a "chicken line" trading floor.

What I've been able to glean:

The LOOP is just a giant single point mooring that sits in 100ft of water, roughly, so that a ULCC drawing 75+ft of water can pull up and unload without lightering to smaller ships (the other way it's done).  It lets a ship unload much faster and in worse weather.  These big ships are frigging expense to sit around.  In my day a VLCC wanted $30k/day or more for demurrage.  Now that shipping is tight you have to  pay double that.  Cutting 3-4 days of demurrage off the bill is big money over time.

Port Foucheron looks like a gathering area for all the offshore pipelines from the individual platforms.