It’s an expression of surprise or disbelief, in the same vein as “oh my goodness.” It’s a bit old-fashioned; nowadays you’ll mostly hear it in cartoons and the like, uttered by little old ladies.
No shade to DamnInteresting; I find it quite endearing.
“Nobody [does thing] anymore” is a common euphemism for “very few people [do thing] now, compared to in the past”. The author is correct about this with respect to cursive, at least in the US. I think you know this as well, as you acknowledge your outlier status.
No shade to DamnInteresting; I find it quite endearing.