According to my personal implanted Babel Fish, "Signalverlaufsdaten" translates as "signal process data". Which makes it sound like the signal output from some sort of processing? What is the data structure of it? If you open your help window and hover over a wiring carrying the "Signalverlaufsdaten" with the wiring tool the help window should show what it is made up of.
Concerning your second question, save a copy of the export VI with a different name and modify it to not insert the datestamp or header. See attached...
Mike...
PS: The attached VI is a very quick modification. I haven't prettied it up any, I just stripped out the unwanted parts.