I love my Shimano mountain bike shoes (SH-MO38W) I'm on my second pair; my first pair finally wore out after 10 years. They don't have a slick sole. I wear them when I ride my road bikes. The shoes I would really like to have (Sidi) cost way too much than is reasonable, and I'm happy with my Shimanos.

Clipping in and out takes practice. It's good to practice on a trainer and then on the grass until you get the hang of it. Expect to fall. I've fallen a handful of times in my 23 years of riding clipless. The last time I fell was just a few days ago. It happens, but if you practice (and practice falling--on grass), it'll be less of an issue fearwise.