No way to know what his dad was like from those articles. First of all, his dad training Lou was very likely a suggestion from the producers of the movie, just as they asked that their training footage come from R&J Gym in Brooklyn when in fact Lou was training in Venice. Staged for dramatic effect. His real trainer might've been the guy handing him the barbell during that strip set. It made a difference; Matty's persona helped the movie, which no one acknowledges. Lou himself was too quiet and unsure of himself at that age to make an interesting opponent by himself.
As far as steroids, it's obvious that Lou had numerous BB guys around him-Lurie, his trainer (not his dad), etc. so it could have come from anywhere without his dad knowing the specifics.