The premise from the mindless Assad supporters (NOT the anti-war people, they are a totally different faction IMO who are skeptical of the rebels and Assad) is that there once was a guy named Bashar Al Assad who was running his country and democratizing slowly during the Arab spring. He was particularly liked by the people, even though he had inherited a dictatorship unjustly from his father, who has done genocides against Sunni's
http://en.wikipedia.org/wiki/Hama_massacre
So the Arab spring comes along, and people are protesting in the streets of every Arab city from Doha to Damascus, and the protests are based largely on economics. The poorer oil-less countries seemed to have the most violent protests as they were the hardest hit, and so Damascus becomes a protest ground for a number of days and weeks.
Libyan dictator Ghadaffi starts bombing his own citizens in Libya as a response to the protesting; there is really no disputing this, there has been no real opposition to these facts, and they are accepted. The international community stepped in and we have whatever we have today in Libya.
The situation is trickier in Syria because the leader of Syria is an Alawite, which is a "sect of Islam" (they are not Muslims whatsoever but that is another topic) and that group only accounts for about 10-15%, with the overwhelming majority being Sunni Muslims and with a size able minority of Christians. So the Alawites to their credit favour secularism because they prefer to keep the tenets of their religion secret, as they wouldn't want to be accused of heresy (barbaric I know) and the Sunni's want to implement some degree of Islamic values in their government, on the far right being Saudi Arabia, and on the moderate side being Malaysia or Indonesia. As a result of the variation, there are different people protesting in the streets for different things at this point. Some people want secular democracy without Bashar, some people want Malaysia, and some people want Afghanistan in 1998. They all wanted one thing, Bashar to go, and he refused to even entertain the idea.
The protests turned from thousands to 10's of thousands, then into the hundreds of thousands, then into the millions. The Army had the same response, go to the villages and crack down. Sometimes they would shell the villages, then they started turning up the violence. Eventually armed civilians started blocking the Army's movement into villages, threatening violence against them, and this is an important turning point.
Friday after Friday of escalation and increasing protests till we get to Sept 2011, the benevolent Russians are getting their flags burned in the streets because they are blocking a resolution even CONDEMNING the attacks against protesters, even though the whole world sees it. The Turkish cut all ties with Assad after seeing how much more violent he is getting. Even IRAN starts to condemn the massacre in Syria, which at this point is reaching the thousands in body count and is totally one sided; there is no real FSA at this point or Al Qaeda or anybody.
Fast forward June 2012... the war as we know it is officially ON... the FSA forces number around 40-50k and begin fighting in towns and cities against the regime with the aim of toppling the regime. The FSA forces grow to about 100k many of them being defectors of the Syrian Army and we got ourselves a slobber knocker. Al Q joins the Party around this time but their numbers are very weak... never cracking 10k in Syria... infact the total number of Al Q in Iraq at any given point was around 10k and that was in a war against America... these are also very liberal American estimates who seek to exaggerate the threat of Al Q anywhere. The Al Q fighters are more and more successful and they go under the name Al Nusra. They have external training and are fanatical, doing suicide bombings and whatnot, getting funding from shady Arab sources in the hopes that if the FSA does win, the Nusra can be the largest faction and co-opt the revolution for their backers. This is where the CIA plays in. When it was thought to be an almost certainty that the FSA was going to win, the CIA started to support the FSA in the hopes that they would have the strength to fight off Al Nusra, chase them into the highlands and leave them open for our friend Pred the friendly Drone. However since the regime had started to make advances against the rebels due to their air superiority and new weapons shipments from Russia, this has become a tricky gambit.
Fast forward this supposed chem-weapons attack. The assertion from Assad supporters is that the whole thing is either staged or a false flag. Cognitive dissidence aside lets just get to what we know and what we don't know. What we do know is that it was a chemical attack on a rebel controlled district of Damascus. There is apparently American military intelligence that proves conclusively that it was Assad's forces who fired it, and it is my bias to agree that such evidence does exist based on the evidence they've released, however for the sake of being consistent lets continue to go the basis of confirmed facts, which this is not yet a part of. If the rebels had used the weapons in order to garner international support, you have to ask yourself, why not do this when they were winning, the west would have been more open to killing a dying regime. Also, if they have the ability to deliver chemical weapons, why not keep delivering them and using them against regime troops? Wouldn't they just win the war indigenous? Finally, why are we suspending logic when Assad has among the worlds largest supplies of chemical weapons and historically him and his father have had zero problem with killing thousands of his own people? His willingness to give up the weapons right now in a plea deal for me seals the deal that he did use it and got away with it. People saying that the Regime wouldn't use it because it would be stupid, they wouldn't get away with it, are and were totally wrong. They and the Russians clearly calculated this and now it appears he's 100% getting away with using chemical weapons from my perspective. This sends a message to the FSA that NATO is not coming to their rescue and that the Regime has strong friends as well, and that they can act with impunity.
Ironically this is the short version of my opinion, there is more which includes Israel, Saudi's, Turkey, Iran/Hezbollah etc, but this is a basis for the answering of the questions posed by the OP.
This is coming from the guy who said white cacs were the first to cross the Bering Strait, yeah ok cac. Keep living your fantasies. 
not this cac again yo cac st0rmfr0nt is that way