So, my question again is what characteristics do matter the most in their effect on seakindliness/seaworthiness of an offshore boat?
That's a question that has been subjected to much discussion, consideration postulation, debate and hypothesis. The end result of this was a weighted table of measurements that attempted to answer the question you posed. You used that table yourself and...
Based on that consensus, the Wauqiez is indeed a slightly less seaworthy seaboat than some others.
However, if you love the Wauqiez and if you believe it is the right boat for you to sail, then buy it.
As you read this there are thousands and thousands of people cruising the oceans. A tiny number of them are sailing Valiants, Cape Dories or Pacific Seacraft. Very few boats/crews are going to come to bad ends and I don't think that they are enjoying their cruising any less because they don't have the "right" boat.
Good Luck !