I'm not sure I understand the problem?
If you ride clipless for long enough you'll gain a sort of muscle memory of how to plant your foot so you clip in on the first downstroke (almost) every time. As mentioned, you can adjust the tension to make clipping/unclipping easier or firmer.
As for the shoes reclipping themselves before a dismount, you may be unclipping too early. There is no reason to unclip before you are ready to physically remove your foot from the pedal. If you unclip as you remove your foot there is no chance of it accidentally reclipping.
Finally, there are probably 100 threads here at BF.net about falling becasue of clipless pedals. EVERYONE falls when they are first learning to use them, it's just a fact of life. I got my first pair of SPD pedals almost a decade ago and I still fall at least once a year because i couldn't/didn't unclip fast enough. Even still, I love my clipless pedals and I can't immagine going back to platforms on any of my bikes*.
*I did put Shimano PD-M324's on my commuter/utility bike because they are uber-functional; I still ride the clipless side 90% of the time.