So I hooked up a keyboard to my Xbox one and turns out it partly works.....
These are list of what works.
1,2,3,4,5,6,7,8,9,0 : equipment and weapons
Space-bar : jump
Tab : select
Escape: start
Enter: accept other half of a button of controller.
Arrow keys: are directional but doesn't move character just select items in menus.
So my conclusion is rare is being lazy or something not to complete keyboard and mouse support. Maybe they are scared of us Xbox users kicking butt with keyboard and mouse. At least allow me to use the chat I find it annoying I can do so much but talk with keyboard. ;-) come on rare test my PC skills by giving me support completely and see my 28 years of PC shooters with keyboard and mouse. I'd rule the seas if I could use both because when I'd wanna be lazy I can use controller keyboard mouse when I want wreck for PvP.