Your main problem is that your patches are separate meshes from your arm. Select the patches and the arm and then go to join->solids. Then select all the points of the arm and go to edit->merge points with a merge distance of 0.001
I looked at the arm and even optimized it a bit, but here's a tip: instead of cutting and slicing the mesh every which way, learn how to uvmap and texture...also remember that you need to try this stuff out in the game every so often to see how it would look. In-game some of these creases won't exist since usually game engines implement a smooth angle of 180 degrees with exceptions to specified smoothing groups/creases. The same goes for the materials in regards to how the game will handle them differently.