I think your shoe choice is fine. For long tours I bring a pair of minimalist shoes that can double as water shoes. Something like the Vibram Five Fingers.

I would just check that your feet are narrow enough that two socks in your cycling shoes is possible. For me, it isn't. I can't even fit my thickest socks, or my Gore-Tex plus wool socks. I can wear Gore-Tex + Liner, or midweight wool, or less.

The experiences of 10 miles in the cold and 50+ miles in the cold are night and day. Choose wisely; you have options when you're too warm, but it sucks to be too cold.