Short answers, pulled from the story.
The Socialist Republic of Romania was the Romanian communist state that existed from 1947 to the Revolution of 1989. From 1947 to 1965, it was called the Romanian People's Republic. It was a single-party state governed by the Romanian Communist Party and a member of the Warsaw Pact.
King Michael I was forced to abdicate on the 30th of December 1947. With pro-Communist troops surrounding his palace in Bucharest and his telephone lines cut, he signed a pretyped instrument of abdication presented to him by Groza and Gheorghiu-Dej.
The Pitești experiment was a brainwashing program conducted between 1949 and 1952 at the political prison in Pitești, a city about 120 kilometers northwest of Bucharest. It used psychological and physical torture to attempt to "reeducate" political prisoners. Tens of people died, and many survivors later took their own lives or were institutionalized.
Ceaușescu rose to power after the death of Gheorghiu-Dej in 1965, following a power struggle within the party. He had been an obscure figure, briefly part of a collective secretariat that ran the party in 1954, before becoming General Secretary in 1965 and President in 1974.
The collapse began with protests in Timișoara on the 16th of December 1989, triggered by the attempted eviction of pastor László Tőkés. Soldiers killed about 100 protesters on the 17th of December. On the 21st, a Bucharest rally turned against Ceaușescu as the crowd openly booed him. He fled by helicopter but was captured in Târgoviște, tried, and executed by firing squad on the 25th of December 1989.
Polls taken decades after the republic's fall show that more than 53% of Romanians said they would prefer to live again under the Communist regime, and 63% said their lives were better under it. In December 2018-64% of those surveyed held a good opinion of Ceaușescu, making him the president with the highest approval rating in Romanian poll history at that time.