Wow that gave me a pretty nice start! Although it is not ideal for situations like dropping down where the speed can be too much for interpolation to catch up. I interpolated on the Z and X axis with a 2D Vector and it looks promising.
Used a virtual bone instead of directly moving the camera though so that hand IK could align with the camera avoiding the shake. Will run some tests and see if I can get a good system ready 
Update : This is already usable for regular fps without any weapons and stuff but when I try to do weapons with this the gun is bouncing lot. Any way to keep it aligned in front of the camera. Star Citizen devs said that they used a separate IK for first person and I tried two bone IK which doesnt seem to work. Any ideas?