Odds of Getting In
If you read the qualifications, you probably realize it's pretty tough to get into the CIA, especially if you want to be one of the 10% of CIA officers who are field operatives. Your chances will be much better if you've first been honest with yourself about who you are and what you're capable of.
If you're slovenly, slothful, and a bit slow, but you're in complete denial of these things, you're in for a rude awakening. And depending on how slothful you are, you might actuallybe sleeping when they call to turn you down.
As for your sordid past, one traffic violation no biggie, but if you have a ton of them, that may be indicative of a disrespect for the law. No felonies, of course—the CIA doesn't want to be sending a horde of armed liquor store thieves and child molesters overseas. If there are any instances of tax fraud or evasion, you're out.
They'll also look closely at why you got fired from any job, if you have a history of alcohol abuse, and how you've conducted yourself in any online forum. If you have a less-than-pristine track record in any of these areas, they're not going to want you.
By the same token, if you've demonstrated amazing language fluency, technical skills, or the ability to shoot a hummingbird in the eye from a distance of 300 yards with a rubber band, then your odds are going to go up. Especially if a totalitarian hummingbird has risen to power in a foreign state.