Is it possible inside Blender to create a multilayer texture? I find them very useful in Cinme 4D, and then they can be exported as psd or tif to be opened and refined in Photoshop.

Hey Leo, I wish! You can paint with layers using this addon: https://www.blendermarket.com/products/bpainter

But so far there's no way to export as a .psd unfortunately. 

Apologies for not seeing this until now, thankfully we have a new system in place to make sure questions don't go unanswered in the future.