x, y, z, red, green, blue, normals (pitch roll and yaw)
If you are only wanting an xyz point cloud uncheck the boxes that say 'point colors' and 'point normals' during export. If your post-processing software can accept these values then leave them checked, up to you? I personally do not use the point normals but I do utilise the rgb values.
As for the las file... not too sure?? I think I may have encountered that error before but I cannot remember what the problem was?