I create the UV maps within Blender and ensure that applied materials use the correct map inside Unreal.
Regarding the rotation of meshes, Blender and Unreal consider different axis to be forwards. You have to change some settings in the Blender export to accommodate for this. By default it would also export everything in your Blender scene so again in the export settings you can set to only export selected objects. My export settings are below. (They may not be optimal, but they work for me)
Whilst the auto creation of a lightmap within Unreal is true, the textures may also be incorrect after importing due to Unreal and Blender not having 1-1 feature parity for materials. If your Blender material relies upon UV displacement mapping, colour ramps and other nodes it’s often better to bake textures for use within Unreal.
I hope this helps, even if it’s 5 months late.