Conspiracies--what are the chances of them being true?

I am inherently skeptical of conspiracies. Not that I doubt there are people out there trying to manipulate governments, societies, nature, and many other things for personal gain. There undoubtedly are. For the rest of this post I will provide evidence as to why nearly all conspiracy theories are bunk.
In order for a conspiracy to exist, there first of all must be a motive or reason for whatever the alleged conspirators are trying to do. For example, there is a certain group of conspiracy theorists who say that folks way back when wanted it to look like Jesus Christ was the fulfillment of prophecy, so they conspired to make it look like after he died, that he rose again. After all, his body was never found. Those who promote this theory state that either followers of Christ hid the body after he was placed in the cave tomb, or he wasn't really dead when they took him down from the cross, and either went on living somewhere else, or died sometime after he appeared to people. That's the commonly called "Swoon Theory". What would be the motive in such a case? To make it appear that Jesus was resurrected in order to control people?
Later, in this case, Jesus' former disciples died because they promoted the idea that he had risen again. People will die for what they believe is the truth, but not very many people are willing to die for what they know to be a lie. The best possible solution to this dilemma is that those writing about Jesus' death and resurrection, and those who gave their lives for it, actually believed it had happened.
Another thing to consider when examining conspiracy theories is how many people would need to be in on it to pull it off. For example, if there had been a conspiracy within the U.S. government to cause the attacks on 9/11 to happen, there would have needed to be many people involved in pulling it off. Whenever it is necessary to involve large numbers of people in a secret plot, it's wise to consider how many people in the past have kept secrets well. Obviously the larger the number of people involved in such a plot, the more likely it is that at least one will "spill the beans".
There are people out there with motives, money, and time to plan things. However, the human element of being willing to talk for a price comes into it. I was a first hand witness of this many years ago when my friend's vehicle got broken into and things stolen. Later than night, I just happened to walk into a 7-11 where the clerk in the store was talking to another kid who had just walked in about a vehicle that the other kid had broken into. Loose lips sink ships, as they say and those fervently in favor of doing something about a cause are often anxious to brag about it. Conspiracies, therefore, are often revealed, even in the cases where very few people are required to pull them off.