Short answers, pulled from the story.
Stuart Roosa was an American aeronautical engineer, smokejumper, Air Force test pilot, and NASA astronaut who served as Command Module Pilot on Apollo 14. While Alan Shepard and Edgar Mitchell landed on the Moon, Roosa remained in the Command Module Kitty Hawk, conducting experiments from orbit and circling the Moon 34 times over 33 hours.
The Moon Trees are trees grown from seeds that Roosa carried aboard Apollo 14 as part of a joint U.S. Forest Service and NASA project. He brought seeds from loblolly pine, sycamore, sweet gum, redwood, and Douglas fir trees; after the mission, those seeds were germinated and planted throughout the United States.
Yes. Before his Air Force career, Roosa worked as a smokejumper for the U.S. Forest Service, parachuting into at least four active fires in Oregon and California during the 1953 fire season.
Roosa was the Capsule Communicator (CAPCOM) at the Launch Complex 34 blockhouse on the 27th of January 1967, when the Apollo 1 fire killed the three crew members during a ground test.
Roosa logged 217 hours in space during his NASA career and accumulated 5,500 total flying hours, with 5,000 of those hours in jet aircraft.
Roosa died on the 12th of December 1994, in Washington, D.C., from complications of pancreatitis at age 61. He is buried in Arlington National Cemetery, where his wife Joan was later interred alongside him after her death on the 30th of October 2007.