I'm thinking about ending the map with the player getting pumped full of neurotoxin.
The result of it would be for the player to fall to the ground and then blackout.
Though instead of "dying" (and failing+reloading the map) i want the player to ragdolise and then blackout.

Is there a way to link the player's view to a ragdoll
(that is also spawned on the exact location of the player's head when the event starts?)

Or would there be a better way to do this?

I can remember that in Garrysmod they had a certain tool that let players ragdolise themselves or other players in multiplayer, generating the same effect.

I would suggest doing it the easy way and keeping the player in first person view. You can create the 'blackout' effect by using an env_fade and create a camera entity that moves along a path in order to make it look like you fall.

If I remember correctly Valve uses a simlilar method to create the ending scene where Wheatley gets sucked into space when you place your portal on the moon. The arms holding onto Wheatley are just a vehicle with a series of animations which is played in the scripted scene.

And how would i be animating a nonlinear path, including adding a nonlinear rotation to the camera

func_tracktrain and path_corner's. Make the tracktrain change it's angles near path corners, pump up the wheel width a high value so it seems curved and make a lot of path_corners so it seems as smooth as possible.

I remember in Portal Prelude (a mod for Portal) they had some camera cut scenes every now and then. You could always decompile and see how to do it.