During World War I, many countries suspended their gold standard in varying ways
It's in the first line. The cause here is WWI, not the great depression. These are countries going broke and abandoning the gold standard because of war, not because they are experiencing deflation.
Exactly. The quantity of debt relative to GDP is what is of concern. You are linking to the right things. Go back, reread them and then take a long walk and have a good think.