1. Okay. I'll try again.
In a discussion on the nature of something, by default that something exists. Because you are talking about its nature, abilities, description, whatever. When you are talking about the concept of something, you can also talk about whether the something exists - because you are thinking of it as a concept, not an actual object.
If you respond to a question on the nature of something, then you are considering it as existing. If your response is that it doesn't exist (and you truly think it doesn't exist), you either misread the question or decided to comment on something that wasn't directed at you and are changing the subject.
Based on the comments that several atheists made, and my own personal experience with dealing with Christians and the concept of Jesus, I consider those atheists to be along the lines of someone who accepts God's existence at an unconscious level, but rejects it at a conscious level. Rather than as someone who simply doesn't consider God as existing at all. This is my opinion. And I understand that others do not agree.
2. No, they were wrong. They concluded that other planets did not exist and taught that in colleges as fact. Instead, they should have taught that we do not know. By teaching it as a fact, they possibly hindered the eventual discovery of the data and proper evaluation of that data. By teaching it as an unknown, they could encourage us to improve our techniques and technology in order to expand our base knowledge.
And regardless of what scientists taught, they were wrong. They made the best conclusion they knew how to do, but they were wrong.
Edit: #2 Ninja'd by Dupe. And he said it so much elegantly than I did
