What you really want to avoid is having your wrists bent backwards at all. If anything, you want them bent slightly forward, with your wrist a little bit higher than the keys
Agreed. I, just a few hours ago, attempted to type with my hands going onto the keyboards at a sharp diagonal angle and am finding that it helps with both comfort (my hands and wrists do not hurt at all after extended typing at maximum speed) as well as accuracy; normally it would make shift positioning awkward, but Stamina taught me to use opposite hand shift to rectify that issue.
I recommend trying this: leave your elbows on a wrist rest and allow your hands onto the keyboard so that they point diagonally upwards and in; an angle suitable to you will be discovered.
The logic behind this being that fingers cannot move laterally, so angling them allows them to move laterally without stretching the wrist. Personally, it halves the number of keys which I have to reach for, and doesn't add any different ones. However, I use Dvorak which I assume already does wonders for my hands. I type from 120-140 wpm, and doing that for more than a handful of time on Qwerty would probably render me incapable of fencing.