C.D.
Hi B.,
It's a lifestyle call for you. Here's how I do it--I land somewhere in the middle.
I take my shoes off at my house, even when I had a dog (she died recently), and now my 4 year old and my 20 month old take their shoes off on their own. It's not a bad habit to get into if you like clean floors. And I do. I don't, however, ask my guests to take off their shoes, but about half of them get the hint when they see our shoes piled up at the door. If they don't, I don't sweat it. Any amount of shoe-free walking is helpful.
As for crawling in public places--I NEVER did. That totally grosses me out, but if you can figure out a way to contain your mobile one (in your arms,in a carrier, in a stroller) that would better then wondering where other people's shoes have been right before your baby puts her hands there.
This is just my style but you'll see what is practical for yours. :-)