For the facing problem in Blender you don’t need to unparent model and armature, when exporting to FBX you can choose the option "Forward " , i just put “Y Forward” and it works. About scaling i didn’t had to deal with them as importing the mesh first than importing the skeleton having T pose at frame 0 , resolved the scaling issue.
About physic volumes , as i use only character capsule collision only and no ragdoll , i don’t need them for now.
What is blocking is frames range not respected when importing anims, and there is no tool in the editor to make animations with frames from the track imported.