Any sequence of DNA will be active. There's no such thing as a "blank" sequence of DNA. The activity of the sequence will depend on the molecules in the environment around it. But each base, each atom, no matter what sequence it is in, is active with properties peculiar to it.
Rubbish. If you are attempting to say anything more substantive than "chemicals react with each other," then that implies that EVERY possible iteration of DNA is capable of forming sustainable living beings. You could pour acids and bases into a test tube in every junior high science class in the world and create random, new life forms on demand if that was even remotely true.
It isn't. I can physically form a double-helix structure at home or work, but that doesn't mean that said structure is viable DNA. Likewise, I can physically melt and mold a CD-ROM from scratch, but that doesn't mean that data is automatically valid on it.