re: #3 HappyWarrior

en.wikipedia.org

See also from state.gov :

Bahrain promulgated a constitution and elected its first parliament in 1973, but just 2 years later, in August 1975, the Amir disbanded the National Assembly after it attempted to legislate the end of Al-Khalifa rule and the expulsion of the U.S. Navy from Bahrain.

That seems to be the reason for the USA backing the authoritarian rule there (as well as in other Arab countries).

More:

FOREIGN RELATIONS

Bahrain’s strategic partnership with the U.S. has intensified since 1991. Bahraini pilots flew strikes in Iraq during the 1991 Gulf War, and the country was used as a base for military operations in the Gulf. Bahrain provided logistical and basing support to international maritime interdiction efforts to enforce UN sanctions and prevent illegal smuggling of oil from Iraq in the 1990s. Bahrain also provided extensive basing and overflight clearances for a multitude of U.S. aircraft operating in support of Operation Enduring Freedom (OEF) and Operation Iraqi Freedom (OIF). Bahrain deployed forces in support of coalition operations during both OEF and OIF. Bahrain has delivered humanitarian support and technical training to support the reconstruction of the Iraqi banking sector, and has offered support for each stage of Iraq’s political transformation. Bahrain has also cooperated effectively on criminal investigation issues in support of efforts against terrorism; the Bahrain Monetary Agency (which became the Central Bank of Bahrain in September 2006) moved quickly to restrict terrorists’ ability to transfer funds through Bahrain’s financial system. In October 2006, Bahrain joined the U.S. and 23 other countries in a Proliferation Security Initiative interdiction exercise in the Persian Gulf.

U.S.-BAHRAINI RELATIONS
The American Mission Hospital, affiliated with the National Evangelical Church, has operated continuously in Bahrain for more than a century. Bahrain has also been a base for U.S. naval activity in the Gulf since 1947. When Bahrain became independent, the U.S.-Bahrain relationship was formalized with the establishment of diplomatic relations. The U.S. embassy at Manama was opened September 21, 1971, and a resident ambassador was sent in 1974. The Bahraini embassy in Washington, DC, opened in 1977. In October 1991, Amir Isa bin Salman Al Khalifa made a state visit to Washington. In 2001, Amir Hamad bin Isa Al-Khalifa made his first visit to the U.S. after succeeding his father in 1999. He returned to Washington on an official visit in January 2003. King Hamad made an official visit to Washington in November 2004 to meet with President George W. Bush and cabinet-level officials. In January 2008, President Bush made the first visit by a sitting President to Bahrain. King Hamad visited Washington in March 2008.

Bahrain and the United States signed a Defense Cooperation Agreement in October 1991 granting U.S. forces access to Bahraini facilities and ensuring the right to pre-position material for future crises. Bahrain is the headquarters of the U.S. Navy’s Fifth Fleet. The U.S. designated Bahrain a Major Non-NATO Ally in October 2001. Bahrain and the United States signed a Free Trade Agreement in 2004.

See also state.gov