Clipless pedals and shoes 'are' safer. There is far more chance of you having an accident because your foot has slipped off the pedal than you crashing because your foot is stuck to it.
However there is a compromise. Power Grips:
http://www.cyclestore.co.uk/productDetails.asp?productID=12960&categoryID=719
These allow you to wear any shoes you like, or even boots in the winter, but still have them strapped on. Like clipless shoes, you soon get used to twisting your foot out of them and it becomes something you do without thinking about it.
I bought a pair of clipless shoes years ago but I found them far too draughty, my feet were frozen on anything but the hottest days. Just a poor choice of shoe obviously but a costly mistake, they're still lying in the bottom of the wardrobe being no use for anything else.
I tried Power Grips and they are ideal for me, I have a new set on the desk here as I've worn out my first set. I can use them going to work, going out at the weekend, whatever, and don't need to worry about what shoes I have on. I think they might suit you well too.
The Allan bolts in the front strap clamp are a bit soft and are best replaced. Also, front plate bends out over time and you need to tighten the strap to compensate. However once they've settled down the straps will last for years and need no further attention. Here are some more revues of them:
http://www.mtbr.com/cat/accessories/Extras/power-grips/pedal-strap/PRD_360092_117crx.aspx