Rotation errors when importing an animation from blender to unreal

Hello,

first issue
When i import my animation file from Blender to UE4 the shoulder bones twist in a strange manner, I have tried adjusting the rotation and re import with no success.(see attachment)

Second issue:
I noticed the toes rotate noticeably although it is not at all present in the animation. (see attached images)

My questions are:
-Any guesses as to why this could be happening?
-How does Unreal evaluate its rotation info? is it always xyz even if i set it differently in a Blender?
-My shoulder is a disconnected bone is that a no-no in Unreal imports?

I don’t need a concrete solution but an educated guess and better yet a link to a useful resource on how to tackle this would help me a lot.

Cheers,
Johann Leo