Sorry guys! Been too buzy here…
Good news: Things are getting better with Blender 2.78 RC2 and UE 4.13 final.
Rotation, scaling and mirroring problem persist, but normals are ok if you set “Force One Smooth Shading per Object”.
Sample file @EpicJurre:
https://dl.dropboxusercontent.com/u/33950890/Peu-alembic-LW.rar
Normals problem in eyes are related to scale. If I scale 100x and reexport, every thing is ok.