I want to open a popup window in a scene. So I tried to solve it by doing another scene and push/pop the new scene. but I fall into a cocos2dx bug and I cant do it this way (see my post : Problem with RenderTexture and Nodes using global Z order)
However, assuming I do it as a cocos2:Layer inside an Scene. how can I pause everything on my scene but let my Layer still be active (it may animate as well)
Is it even possible?
Sure, this is a common practice.
I manage to solved it already. but I am not quite sure what you meant in your answer 
What you wanted to do is easily done is all I meant. Glad you have a solution already.
Can’t say it easy making layer which stop all animations of other nodes and take control of the input device. that was not easy. it would have been easy if the GlobalZOrder bug was fixed
If you share some code, perhaps we can help and see what improvements can be made.