The "accidental pull out" has to do with the cleat not the pedal, as someone said in another clipless thread; Shimano makes a cleat that is meant to release in any direction. You may have had the wrong cleats on your shoes, thus letting you release with some upward pressure.

I used two sets of crappy spd pedals and once I set the tension right I had no problem.

As far as getting road shoes with spd's, I'd highly suggest against it. All its going to get you is less traction on your feet + walking around like a duck, and your going to chew up your cleats fast since they wont be recessed in the shoe. Id certainly look into a nice pair of mtb shoes. I have an older pair of sidi mtb shoes and they aren't going anywhere fast at all, had them for around 6 ish years used on the mountain and on the road. I couldn't ask for a better shoe. They are pricey but its worth it in a sort of one time purchase mindset.

good luck, clipless is the way to go for just riding around.

the all direction cleat just makes it easier to accidentally pull out, but it's still possible with the regular one.
It's not like it happens all the time. It's more of a freak occurrence when you pull up really hard on the pedal.