Now that I am back home, I can answer a few of the questions.
I do not think we landed overweight. The pilots mentioned that were were dumping fuel as we headed for Goose Bay.
The plane did not park anywhere near the terminal but at an FBO. I hear that this was because there was not a 777 capable tug in Goose Bay so we had to park in a clear area so they could just pull forward when we left. The passengers that deplaned went into the FBO to stretch their legs.
When we got back to EWR, we did go through immigration and customs. The C customs was empty when we got there and it was a somewhat expedited experience.
I have no idea why door 2L was open all night. I know from watching it was difficult to open and close. The other issue they had was the handle was bitterly cold after the door was open for a time and they were using the oven mittens for gloves.
The passengers around me were mostly rebooking on UA. I heard one mention they rebooked on Cathay. I did not even rebooking since I had no idea when we would get to EWR.
For compensation, one GS on the flight checked an early email after initial arrival in Goose Bay and it was for $500. A second email for compensation came after we left Goose Bay. I have no idea what my offer is since the united care website refuses to function. It looks like it has now been enhanced as part of the web redesign since my last visit