Kingfishers are not one species. There are 90 species within this group. The suborder of kingfishers is split into three families, Alcedinidae, Halcyonidae, and Cerylidae.
Of course they lay eggs, they're birds ! did you not learn anything in biology ?
Most birds' feathers are fairly waterprooof.
They have to preen themselves to keep them waterproof.
The great majority of birds of prey are opportunists - if they can easily catch something edible, even if it is not usual prey, and particularly if they are very hungry, they very often will. No doubt some kingfishers will have been eaten by owls, somewhere, at some time.
AUK - According to the RSPB "The little auk is a small seabird, the size of a starling. It is black above and white below, and in flight it shows dark underwings. It has a black stubby bill, and a short neck and tail. It flies with very fast whirring wingbeats low over the sea. It is a winter visitor to the waters around the UK in small numbers each year. It breeds in the Arctic and winters in the North Atlantic. Some birds enter the North Sea in autumn and large numbers can be seen passing offshore during gales."
# It got it's name simply because when the guy who named it was nameing it he/she saw that it was a brilliant fisher, so it was named the Kingfisher as in it was the king of fishing birds.