I am going to be a brave boy. I'm gonna make a phone call to cancel an appointment that was only technically made for today. *sobbing as the phone rings*
This could just be me reaching but these are just my thoughts. Eddie is naturally eccentric and a little in your face at times but in that cafeteria scene he purposely hypes it up and over exaggerates to not only divert people away from him but his club as a whole (let’s remember he’s older hence why he calls them “little sheepies”) particularly Dustin & Mike with them being the youngest of the hellfire club. He’s simultaneously making people too afraid to confront him and making himself the main target for the likes of Jason who feel superior and unthreatened by him. He’s protecting his fellow nerds and outcasts during a time where it was particularly dangerous.
Now, whether all of the above is intentional or not is up to interpretation but either way the outcome is the same; he’s the leader after all so the disdain is likely to come his way before anyone else.
So yes he comes across as annoying and over the top and you may not like him in that first scene but that’s intentional. You’re seeing him through the eyes of the people in Hawkins.
All of this is why I find the emphasis of him running away and being a coward so upsetting, he was brave from the very beginning. He was brave for staying with Chrissy until the very last second. He was brave for keeping himself together even after seeing the same thing happen again to Patrick. He was brave for jumping in that lake despite how scared he already was after everything he’d seen. He was brave for even joining the gang in the first place, he didn’t have to prove himself after that.
He built that whole club to protect outcasts like himself; embracing being a nerd and metalhead while teaching others to do the same. I think in a time when satanic panic was rampant that was especially brave of him and it hurts my heart that he never saw how brave he really was :(
He may not have been brave in the typical sense of the word but he was brave in all the ways that mattered.