How does one even proc haunting? I can’t seem to find skills that have 5s cooldowns.

Put cd reduction on your items

Don’t the hunter class skills have less than 5s cd?

Wizard: Storm (7), Twister(5). Shatter(4 or 5)?
Rogue: Stealth(12, 14, or 16), Smokebomb (5).
Warrior: Taunt (5)?, Fear (5)?.

these are the ones I know or think I know.

the fastest way to find out is have items with no Cool Down and Dexterity 0, then check each Skill on the Stat Page to see what their Cooldown is.