I use a tented position with a wide split which works well when I am either sitting or standing at my desk. Practicing correct hand placement when typing will help you type faster and take pressure of your wrists (they shouldn’t really be touching the keyboard). Having a wide split placement also keeps my shoulders in a correct anatomical position, so has actually relieved the lower back pain I used to get when at the computer all day.
The Model01 is incredibly flexible in configuration, not just the key layouts and layers, but the positions where you can use it. See the many threads in this forum about tenting, for example Custom Mounts - What are your ideas?
For one handed use, then adding keybindings on a Model01 layer should be able to compensate for your missing hand (you have 32 layers). You could easily have 50 additional keybindings just by defining a new layer. For example, creating a layer that represents 95% of the right hand keyboard, which you can use from just your left hand. That way you can keep the keyboard as separated as you wish and drive both sides from one.
You can also move the mouse using the fn key and wasd and mouse click with fn and f.
I use a trackpad so I can keep it right next to the keyboard, especially when standing at my desk
I learned to type on a mechanical typewriter, so I guess my fingers just have strength. I cycle a lot, so that helps with wrist strength. Using ‘hand grips’ is a good way to increase hand and finger strength.