KEENMen-clearwater Cnx mens Sandal

Do they keep their size? If they are snug now, will they get looser with use?

Do these float if they fall in the water. i'm an sup'er, and sometimes i take em off and slide them under the elastic webbing, afraid of losing them

Does this sandal have good arch support like on a hiking boot?

My husband wears a 13 Wide. Will a 14 fit? (in terms of width)