M424 don't really allow normal shoes. I had a set of M525s M545s (the same but with a metal cage) and the cleat stands proud of the cage quite a bit.
You can buy single sided pedals* that will let you ride in flats on one side of the pedal and let you clip in on the other. As for shoes, something like the Specialized Tahoe? They're supposed to be wearable as normal shoes.
My preferred solution would be to go for normal clipless pedals + shoes you can walk in as well, then not ride in normal shoes. I know you're wanting to not be clipped in but after not very long it will be completely second nature and you won't even notice you're using them.
*I'm not sure if this is what you meant by half clips, but in case you meant toe-clips, don't do it.