Low quality magnets are weaker than good rare earth magnets so that part is definitely wrong. Also the placement is far enough away from the camera that I can't imagine it causing trouble for autofocus. LCD screens have no sensitivity to magnets so the only way I can see a problem there is if the material over the magnet is low quality and causes scratches. The only problem I have is with the compass so I remove the case when doing photospheres or anything that uses the compass.
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