I wouldn't overthink this. I've toured with toe clips and straps and ordinary shoes. So have a lot of other people. Try it and see what you think. There's a trade off; you save on not having to take a 2d pair of walking shoes when touring but the sole won't be as stiff as a cycling shoe. Stiff soles help you transfer power better but too stiff and they're tough to walk on.

Another possibility I've been thinking about is picking up a pair of bmx style shoes, like a 5.10 shoe. They're designed for bmx pedals but I think they could work well for touring as well.

The MKS GR9 that [MENTION=154351]imi[/MENTION] mentioned in post 2 look like a good design for touring as well. The platform will help provide support if cycle with ordinary shoes. I'm a huge fan of MKS pedals in any case; they're inexpensive and well made.