Before you read this, I'm just letting you know I'm basing this off of the manga + webcomic, so if you haven't caught up to the webcomic and don't want to be spoiled, ignore it.
Bang is too high, he can't touch Flashy, and he can't do any serious damage to Darkshine. Darkshine outlasts him, and Flashy well he's not getting touched, his performance against Awakened Garou is levels above anything Bang can even dream of. Those two are clearly above him based on current webcomic feats. Barring any major changes from the manga, that's not going to change.
Amai Mask should be placed above Bang (and Atomic) as well based off his performance against Evil Natural Water + Black Sperm, he didn't break a sweat dealing with two of the absolute strongest Dragons simultaneously, Bang earlier got destroyed by a couple of dragons (it was too great a task for him to take on more than 1 at a time). Amai also has a regen factor ontop of that, making it almost unfair. He's above Bang based off the webcomic (now that Child Emperor is taking on Evil Natural Water, this might be subject to change).
Child Emperor is also arguably higher than Bang. He can deal with some monsters that would be too much for Bang. Bang is pretty much only good for fighting straight forward humans or humanoids (more or less stated in the manga and backed with feats). Child Emperor can take on any opponent Bang can, but Bang can't deal with some opponents Child Emperor would be able to perform against (possibly Centichoro and Rover, Phoenix Man, and if he takes Evil Natural Water), by default he should be higher in a power ranking, he covers more/stronger opponents.
Zombie man can possibly outlast Bang as well considering Bang's age (he's shown signs of age multiple times), he's bound to get tired eventually. Zombie man will keep regenerating, just like he did against Full Strength Carnage Kabuto a Dragon lvl threat, as well as Homeless Emperor who even had a specific matchup advantage against him. Zombieman is a bit trickier to place in a power ranking, but the point is you got Bang way too high on your list he is exploitable compared to the definitive top 5 (Blast, Metal Knight, Tatsumaki, FF, Darkshine).
The rest are debatable.