Short answers, pulled from the story.
Don Luis José de la Rocha Camiña constructed the first structure of Malacañang Palace as a summer retreat for his family along the Pasig River. He designed the property with stone walls, a bathhouse on the water, and gardens enclosed by a stone fence.
President Ramon Magsaysay restored the original spelling Malacañang upon his inauguration on the 30th of December 1953. Modern policy distinguishes between Malacañan Palace for official residence and Malacañang for the office itself.
Rafaél de Echagüe y Bermingham became the first Spanish governor-general to reside at Malacañang after an earthquake destroyed the Palacio del Gobernador inside Intramuros on the 3rd of June 1863. He added a wooden two-story extension to the back because he found the existing structure too small.
First Lady Imelda Marcos oversaw extensive reconstruction of the main building from 1978 to 1979 while architect Jorge Ramos directed the project. The old structure was gutted almost entirely due to unstable floors and leaking roofs, then rebuilt using poured concrete, steel girders, and trusses concealed beneath ornate hardwood panels.
President Manuel L. Quezon became the first Filipino resident when the Commonwealth formed on the 15th of November 1935. Emilio Aguinaldo did not reside there but was held as a political prisoner for weeks in 1901 after capture.