THIS IS A LIST OF PERK-CONCEPTS THAT I FOUND INTERESTING.

I'll update it whenever I think of something new and interesting (at least for me).

SURVIVOR:

1. DANGER-SENSE

You focus on your sense of hearing for when you can't see.
Sounds made by the killer are 20%/35%/50% (Possible change: 10%/25%/40%) louder for you than usual.
(For example Breathing and Footsteps. Basically Stridor for survivors)
"I can hear them breathing in my neck..."

2. CAREFULL MOVEMENT

You keep your body calm and try not to make unnecessary sounds.
Slowly vaulting and hiding in Lockers takes 20%/15%/10% longer but doesn't make any sound while performing them.
"No sounds, no signs."

3. TRACK HUNTER

You've spend enough time in chases that you can recognize it's signs by now.
You can see footstep marks made by other Survivors (Possible change: The killer creates footstep marks aswell) for 3/4/5 seconds.
"Looks like a chase."

4. EXPERIENCED ARTISAN

You've lived through this Limbo enough times, that you've got a feeling for your skills and concentrate on them more.
While outside of the Terror Radius, Skill Checks on repairing and sabotaging have a 3%/6%/10% increased chance of appearing.
"This won't be the last one."

5. SAVE ZONE

You try to stay away from certain death and learned to feel it's presence.
Unlocks potential in one's Aura reading ability. Hook's Auras are revealed to you when standing within 8/16/24 metres. -/- /slightly/moderatly increases Luck.
"They're made from cold metal, but they're warm from the neverending streams of blood..."

6. REPEATED SAFETY

They saved you once, maybe they can save you a second time.
You can rearrange a thrown pallet next to you, if you are outside of the Terror Radius. This action can be cancelled by the Killer breaking the affected Pallet. This perk has a cooldown of 75/60/45 seconds.
(Side note: It's a 3-second-long animation.)
"Maybe... it can hold another beating."

KILLER:

1. IMPATIENT RAGE

The longer the chase takes, the stronger the urge of killing becomes.
When you reach Bloodlust 3/2/2 during a chase, the chased survivor suffers from the Exposed Status Effect for 5/5/10 seconds.
"I will get you, eventually."

2. FALSE CONFIDENCE

Stopping you just makes you even more angry.
Everytime a survivor stuns you, gain a Token up to 3/4/5. You reach Bloodlust 0.5 seconds quicker for each Token (up to 1.5/2/2.5 seconds earlier).
"They think they're clever..."

3. HERD OF PREY

Having all of them around you fills you with the joy of a predator.
Your movement speed is increased when more than one survivor is within 12/14/16 metres.
2 survivors nearby increases movement speed by 1%/2%/3%.
3 survivors nearby increases movement speed by 2%/3%/4%.
4 survivors nearby increases movement speed by 3%/4%/5%.
"I will kill all of you!"

4. SINISTER PLEASURE

Having Survivors hanging down there makes you even more eager to add others to the collection.
For each survivor hooked in the Basement you gain a Token up to 1/2/3. This Token will be removed when the survivor is unhooked, but not if the survivor gets sacrificed.
For each Token your lunge-movement-speed is increased by 13% (up to 163%/176%/189% lunge-movement-speed).
(Range of lunge in 0.3 seconds ~ 2m + (0.5m / 3) * Number-of-Tokens (= up to 2.5m))
"More... I... I need more..."

5. HEX: DARK-ROULETTE

Totems have never been harmfull, until your deviousness brought you an idea!
This Hex Totem turns up to 4/3/2 Dull Totems into fake Hex Totems. When a survivor cleanses any of those affected Totems, their action speed is decreased by 5% for 20/40/60 seconds, their Auras are being revealed to you for 0/5/10 seconds and they suffer from the Hindered Status Effect for 0/0/5 seconds.
Removing the Hex Totem of Hex: Totem-Roulette turns the affected Totems back into Dull Totems, making them harmless again.
(Side note: If Hex: No one escapes Death activates while no Dull Totem is available, it replaces one of the affected Hex Totems instead!)
"The odds are strongly against them!"

6. PRECAUTIONARY ACTION

Your foresight makes you want to prevent own harm.
You can destroy any unused Pallet next to you. This action can be cancelled by a Survivor throwing down the affected Pallet. This perk has a cooldown of 75/60/45 seconds.
(Side note: It's a 3-second-long animation.)
"It's already gone, you foolish thing."