Can't believe I stumped you all, okay here's some hints that should really help.
Round 5 Bizarro Kipman!!
For some of these, each part of the hint represents a word in the song/band title, but in others both parts of the hint can both represent a single name entry.
1. to cut/Bloodletting - number/Judas Priest song (hint: Greek meaning - Sad Wings)
2. Aquaman connection/Corn - Political term (hint: very very close intimate connection - alliance)
3. Cough/Adrian - hitting the ton/asshole who loves themselves - SikTh - Century of the Narcissist - (romdrums)
4. Shark nickname/Yes - Propel with force/Anselmo (hint: Aussie sport/guitar - meaning/band)
5. Australian sportswear/Sea Edge - Acute or referred/Not leaving - Lorna Shore - Pain Remains Part 2 (Lonk)
6. Alter or modify/non clear food wrap - Building outline/GTFO room - Amendfoil - Skyline Escape - (TAC)
7. 3 letter Acronym/Don't do this - Number close to 100/miserable human (hint: American rock band - number is in the 90's) - CKY - 96 Quite Bitter Beings
8. Extended word that's not actually a word?/Things that will necessarily happen in the future - Do not want/Betrayal (Word starts with D from France, metal - another word for both)
9. Martin ADP album artist/Boss - Trivium song/Up - (hint: google for the first part for the album/blatantly obvious nickname - Growl less Trivium)
10. Joe Surfer/Claw - Pushback/5 years from now - (hint: Think of a Joe that had a song about a surfer/Literally 5 years from now) - Silver Talon - Resistance 2029 (TAC)
11. Cough/Adrian - Joker/Collective humans - SikTh - Riddles of Humanity - (romdrums/ariich)
12. Trio of Subordinates - Before me/Year (hint: Lead by a punk icon - A year well before I was born)
13. Expressing movement or action/Large Gap - Never got this far in a book/out of the packet/the way we look at things
14. We Want ...?.../Open area - of play/get to one place to another (hint: Live album - word that fits before 'of play'
15. Smith/Dickinson credit - Athena/Your dream crush is - Darkest Hour - TAC
16. Mentally unsound/triple dance - evil being/kind being - Psychotic Waltz - Devils and Angels (Evermind)
17. Egypt horizon/another word for P in certain organization name found a certain somewhere - DT ballad - (hint: Egyptian word for the horizon/My organization - Mid career DT)
18. Maximum/Minimum - Metal does this to you/kind of measurement of time - (value of a function - it makes you what?/Eternity
Go!