Hello to break down your list.
1: HL2 content is not packed with Garry's Mod so we cannot use those models as we have no way of providing it to players without HL2, so they would see errors.
2: Same for CS content.
3: Effects are cool, but we have them blocked for a reason.
I skimmed the list, but the props will remain blacklisted.
If you think there is one I might have overlooked that should be whitelisted feel free to remake the report.