I think the important thing to remember is that Elements of Style (including, in general, grammar, syntax, paragraphing etc) is merely a description of what was the standard at a point in time. Style evolves, so your best indicator of what is 'standard' or 'generally acceptable' nowadays is found in the most recent publications. Just read lots! :-) It still may be interesting to know, good to have a look but no need to wave it around like a prosecuting barrister. ;-)

"Elements of Style" has been described (and rightly so) as aging zombie of a book. It was excessively bossy and overly strict when it was written and time has not improved it. There are many other recent books which would be much more useful if you want to write well in English.