CrocsUnisex-Adult Mellow Clog

I wear 11 should I order an 11 in this

Are they good for walking outdoors? Do they stay on well? Thanks for your replies!

Are these really just slippers? Reading between the lines of the description kind of conjures that message. Like, will they not hold up to walking on

I wear 9.5, should I still go 1 size down to an 8?