Assad is illegitimate, because the received power from his father.
In this case, parviteli Saudi Arabia and Qatar also illegitimate, that does not prevent the United States to support them.
In Syria, violate the rights of the Sunnis.
Absolute nonsense. Syria - a secular country. Therefore, people of all religions and faiths in Syria have equal rights. For example, the defense minister in Syria - a Sunni. The head of the General Staff of the army of Syria - a Sunni. Syrian Sunni theologians in their majority supported Assad. A huge number of party members Assad - the Sunnis. Moreover, the wife of Bashar al-Assad (very famous and popular people in Syria) is a Sunni.
ISIS originated in Syria due to the infringement of the rights of Sunnis.
ISIS originated in Iraq. The cause of the ISIS is the invasion of the American Army in sovereign Iraq (without UN Security Council resolutions and the invitation of the Government of Iraq, that is in violation of international law).
Russia has quarreled with all the Sunni world.
Egypt supported the peacekeeping activities of Russia in Syria. Moreover, in Russia the majority of Muslims - Sunnis.
Assad is fighting against the "Free Syrian Army".
Such units as the "Free Syrian Army" simply does not exist. This organization is an invention of the United States. Russia has repeatedly publicly request to its leaders to get in touch with Russia, to be able to coordinate the fight against ISIS. In connection no one came. Russian diplomats appealed to the United States to provide the names of the leaders of the "FSA". US could not name a single name.
Russia has no right to fight in Syria against ISIS.
Speaking from the perspective of international law, it is Russia entitled to it (Bashar Assad officially appealed to Russia for help). But again, the Americans are international criminals. Since the United States invaded again in a foreign country without a UN Security Council resolution and without a request from the President of Syria.
Russian bombs kill civilians.
No confirmation of this information from Syria is not available. The only source of such information - "Syrian Observatory For Human Rights" (an organization which employs only one person).
To be honest, I'm not at all surprised by the flood of lies from the US. The United States has never been the presence of conscience.
Note. The Ukrainian side has already offered to publish on the website of "The Peacemaker" these Russian pilots who are fighting in Syria. As stated by the Ukrainian deputy Viktor Gerashchenko, it will be done so that the militants could find ISIS then pilots and their families, and revenge.