YES, Steve has had great character development! Totally agree with you that he has been a great surprise. When he went back into the house to beat on the Demogorgon in Season 1?! And then was cool with Nancy giving Jonathan a new camera? Totally unexpected.
I agree with your thoughts about Jonathan...besides Billy and 008's gang he's probably my least-favorite character on the show. He just does nothing for me (Nancy at least became something of a badass, but I wouldn't mind way less focus on her in Season 3). And HECK YES it was creepy that he was out there taking pictures!!
WHAT EVEN.