Your post makes it sound like you are trying to pedal on the platform side with clipless shoes (i.e. shoes with cleats). Wear normal shoes and you shouldn't have problems accidentally clipping in. The platforms on single sided pedals were never meant to be used with clipless shoes (I'm not sure how your feet are not constantly slipping off). I would keep your current equipment and just use the clipped side. With more use unclipping will become second nature.

By the way, how does using clipless help when you are coasting?