I also have Sidi Mega Dominator shoes. No, I would not want to walk very far in them either. I also have semi-custom footbeds. An orthopedic technician modified a set of Simple Feet foot beds for me by gluing foam on the bottom, and then milling the foam to cant the foot beds. It is a correction that I need. You should be able to replace the foot beds in your shoes to make them more comfortable.
My other shoes are a discontinued Specialized shoe that just happen to have a wide toe box.
I don't think I could go hiking in any of the bike shoes I have ever owned.
I did once ride up to site on the Goulais River near Searchmont, Ontario. Darn near killed myself climbing on the rocks as the steel cleats stuck out far enough to be unexpectedly slippery. I would have been a lot safer had I brought tennis shoes.