I love this game. And after reading all your awesome ideas I only can say this:

For the good of the game, lets hope that Regalis does not put this into the final version. Optional or not, funny achievement do not fit in a terror game

WTF BRO: Beat the whole game on Keter and get the nuke Gate B ending.

GAME OVER, MAN!: Get Scp-173, 106 and 096 on your Navigator all at once.

SUP RADICAL LARRY: Go into the Matinence tunnels and go into the PD.

must...keep...RUNNING: Sprint for 30 seconds with the extended sprint gas mask.

I think most if not all of these achievements in general would detract from the game. Sorry.

 if
  SCP-682 added in game.
    if
       MTF in same room.
       then        else
no achivement.
(BTW it's supposed for "Sig-Eight-Two" SCP game...)

Some more:

Do I move? - Die from 173 in the intro.

Screw physics. - Stay in the Pocket DImension for 20 minutes.

I am OUTTA here! - Beat the game within 8 minutes.

Housekeeping - Die from 106 in front of 826.

One SCP to rule them all... - Wear SCP 426

Armed and ready - Have the S-Nav Ultimate, Upgraded gas mask, and Radio all at the same time.

Computer Failure - Have a door slam in front of you from 079.

Vertigo - Play the game using wireframe.

Don't worry, i'm a doctor! - Bandage your bullet wound.

The Anomalous Houdini - Escape from every hostile NPC.

I am so freaking READY - Simultaneously use 426, 420-J, and 914 on yourself.

Is this your card? - Escape from any SCP using the tesla gate.

These achievements should be implemented if they ever go onto Greenlight.