Just watched a PBS two-hour documentary on the Genome Project. At the end, it talked about where research since that project has been taken off to. We're part of that next step. However...

What I found surprising to learn is that only a small percentage of our DNA has anything to do with us. Most of the DNA simply self-replicates itself into the next DNA. They called that part of the DNA "freeloaders" and even sort of like parasites that do no harm.

First off, is what they said in that PBS special true about the majority of our DNA being worthless junk?

Second, saying it is true, what part of the DNA are we folding here? I assume (probably wrongly) that we're building proteins using a DNA model then folding them. True?

Lastly, what would happen if we decided to cut out this useless junk from our DNA? Say we don't want the useless stuff to be passed along to our descendents and we snip it out.