I understand that might haven't been added for some possibly obvious reasons but what if it's still possible...
1)Behind Glow
Ah those nice days with behind glow...That was awesome with Construct Classic! Why not add the same thing to C2? I used to combine it with some other effects and got an awesome picture in the end :)
2)Add "radius" parameter to glow and blur effects
3)Add "grain size" and "speed" to noise effect
4)Motion Blur(I know it's almost impossible but hey I have dreams too)
I guess that's all for now.