re: So, is Johnny Lawrence the bad guy in Cobra Kai or no?

The true villain is D-man. He constantly provoked conflicts and then played the victim whenever he met comeuppance for his cowardly actions. These actions sent Hawk on his spiral that had Moon dump him, motivating the sacking of Miyagi Dojo. Then, just when the Cobra Kai and Miyagi Do kids were all coming together as friends and Hawk was starting to learn some humility to mellow out and relax, he pores gasoline on the fire and restarts the karate war that boils over the next week at school.

Robby and Samantha especially also share some culpability, but Demetrie is the true villain of the series.