Short answers, pulled from the story.
The Empire Strikes Back was directed by Irvin Kershner. George Lucas, who had directed Star Wars, handed the responsibility to Kershner to avoid the stress of directing again, hiring him in February 1978 after considering around 100 candidates.
The final production budget for The Empire Strikes Back was $30.5 million, nearly four times the original $8 million plan. Costs escalated due to severe weather in Norway, a fire at Elstree Studios, schedule overruns of more than fifty days, and a financing crisis that required Bank of Boston to refinance the loan mid-production.
The Empire Strikes Back earned approximately $401.5 million worldwide during its original 1980 release, making it the highest-grossing film of that year. Cumulative releases have raised the worldwide total to $549-$550 million, equivalent to $920.8 million adjusted for inflation in North America.
The screenplay was written by Leigh Brackett and Lawrence Kasdan, based on a story by George Lucas. Brackett completed the first draft in February 1978 before dying of cancer on March 18 of that year. Lucas wrote the second draft himself, then hired Kasdan in June 1978 to refine the script for $60,000.
David Prowse, who was known for leaking information, was given a false line to read on set: "Obi-Wan Kenobi is your father." Only director Irvin Kershner, the producers, and Mark Hamill knew the actual dialogue. James Earl Jones recorded Vader's real line in late 1979 and early 1980 during post-production.
The United States Library of Congress selected The Empire Strikes Back for preservation in the National Film Registry in 2010.