Hi could someone please help

"Flip direction" flips the normals of the mesh, turning it inside out, so that would give a see-through effect. 
It's used to create an inside, or to fix a mirrored mesh (they sometimes get flipped normals), and things like that. 


-The line going through the mesh is from normals. Like already suggested, this can be fixed by removing doubles.
-Also make sure your texture fills out the entire UVmap and that the seam on both sides have the same color, or you'll get a weird lighting effect like in the second picture. 
-A specular map (the grey-toned one, or the one with green/rey/red effects - I have yet to learn the difference) with effects left over from the original object you've cloned can also be causing the effects