The whole theme of the series was criticising men who are violent toward women. The first one was even called “Men who hate women” in the original swedish.
Almost all the strong characters in the book are women, and all the most flawed ones are men.
I don’t think Michael Blomqvist was ever described as unattractive and overweight, in fact he was supposed to be very good looking wasn’t he? He was older than Lisbeth of course, but how many young women fantasise about George Clooney, it’s not exactly far fetched. Also his other affairs were with a woman his own age and an older woman, so old fat journo shagging inappropriate young women could hardly be described as a central tenet of the plot.
in answer to the OP – definitely read them in order.