Your text is in color, my comments in black.

Am I correct in my understanding of what you are saying?
Not even close.

You are convinced that spacecraft which have been constructed by extraterrestrials can not exist.
Absolutely FALSE. How could you possibly have gotten that idea from my post. I merely state that there is no credible evidence that any such spacecraft has ever visited the Earth as yet. One MIGHT arrive tomorrow. I am sure that there are millions of intelligent species in the Universe that have developed spacecraft. The issue is have they come here? So far, there is no evidence that they have.

That may sound like a stupid question, specifically after reading your post, but there is a reason why I want to be sure of what you are convinced of at this moment in time.
The total absence of evidence after more than 50 years of investigation convinces me that so far, we have not been visited by ETs.

People often change their mind about personal convictions.
I’m very curious about the process of why a person would change their mind.
If an when some real evidence shows up, I will certainly change my mind on the subject. But not until.

I know that neither you or I can change another persons convictions, but since we are intelligent beings we should be able to discuss in detail the reasons why we believe something to be true.
All positively assertive hypotheses are considered false until proven otherwise.

I’d like to know, if we deduct the “spacecraft” and “distance” out of the extraterrestrial equation, are you still saying that no intelligent life can exist anywhere else in the universe?
Certainly NOT. There are certainly millions of intelligent life forms out there, but it is a big Universe. My own guestimates for the Milky Way Galaxy are: Intelligen life forms: 10 to 100; All planets bearing life; 1,000,000 to 100,000,000

Have you ever considered that there might be extraterrestrial artefacts somewhere but they have not been adequately examined or published?
Sure, they are SOMEWHERE. Just not on Earth. At least, nobody has ever come up with one.

Is there a reason why the information from these meteorite cameras is being suppressed?
http://www.habitablezone.com/space/messages/552551.html
It would be utterly impossible to suppress the information gathered by thousands of competent and properly equipped amateur astronomers distributed in over 150 countries around the Earth.

You are right that when something moves fast enough through the air it causes a sonic boom, but those items that exhibit such behaviour are either meteorites or airplanes and both of those articles push the air in front of them Have you ever wondered what would happen if the object was not pushed but rather pulled through the atmosphere?
Meteorites are not being pushed at all. They are in free fall. ANY object that moves though air at above the speed of sound will generate a shock wave. That is the result of literally millions of experiments in wind tunnels and other devices.

What would happen if the air in front of the craft was diverted to the rear of the craft very smoothly, would there still be a sonic boom?
Certainly. Supersonic motion produces shock waves -- always. Now, if the object were flying HIGH enough, the boom might be diverted by atmospheric refraction and never reach the ground. At low altitudes, where some of these "fantastic speeds" have been reported, itis impossible for the shock wave to be diverted by refraction.

David F Mayer