None of those are out of place.

aquatic animals (otters, beavers, could go on) have plenty of hair. Our lack of hair is function of avoiding parasites using our brain to protect our skin instead of fur armor.

All mammals have fat so I'm not going to get into that one.

All mamals have a swimming reflex, except even though most of them are not aquatic, their reflex actually works. humans that dont spend a long time to learn how to swim ... drown.

but there are features that are very much against us being aquatic: shellfish and fish allergies.