Marvel Chronology Project

Wrecker
Constrictor
Venom
Ant-Man (O'Grady)
Stilt Woman
Bi-Beast
Madame Masque
Black Widow
Captain Britain
Giant-Man
Ultravisions
Abyss
Vengeance
Scarecrow
Taskmaster
Diablo
Whiplash
Max Fury
Hawkeye
Squid
Angel Parvez
Human Torch (Hammond)
Valkyrie

I think the boy's name is just Parvez (so far). Natasha called him Angel as a term of endearment.

I don't think we're seeing the mutant character Abyss here, but rather a dark force called the abyss.

Also appearing:
Letha (on 6:3)
Lascivious (arguably the woman to the left of Letha)

Who's the guy in goggles and face mask between Hawkeye and Squid in that panel?

I don't know if any of the other villains we see in this issue can be identified.

There are three such guys in goggles in that same panel. Maybe they're just generic Shadow Council soldiers.