I read this today in a Miller welding equipment newsletter, some interesting stuff.
First off the second question gives an explaination to something that I put in my "Basics of Basics" inverted welding. It is about welding into the center of the puddle. Here it says how that "insulates" the surrounding metal from the heat, interesting. The third question is really interesting in that they say to put a piece of copper under the weld along the seam as a "heat sink". I have never thought of that, makes sense. The last two questions are a little too "sales pitch" for me, but all in all some good info.