Both of the first two disadvantages do in fact appear to be wrong for the reason that they confuse stable deflation with surprise disinflation.  Does anyone disagree?  Should they be removed?   

 There is, however, an additional unmentioned disadvantage of the gold standard:  To the extent that the increase in supply fails to keep up with the rate of growth, it will be deflationary.  If some prices/wages are in fact sticky, then any pressure (up or down) or those prices will cause a drag on growth.  This is why inflation and inflation expectations are supposed to be kept as stable as possible.  This seems like a major disadvantage and might be the first one listed.  Perhaps the fourth and fifth points could be rewritten in a more general manner with this in mind. 

 I'm wondering if the whole Theory section needs to be rewritten taking into account recent theory including both monetarist and Keynesian perspectives on money/growth.  It certainly needs a lot more academic references.