My hand position moves all over the place as I type

Clearly not a touch typist, then. The hands goes over the F and J (that’s why the bumps are there on the keys, after all) and the fingers extend or fold to reach out to the other keys, but never move. And to use Shift with a key you use the one that’s on the other hand than the one pressing the key. However, that’s the formal version for typewriters, where you don’t have extended sequence pressed with a change key. For long sequences of Ctrl+key, I tend to do as you do and use always the same Ctrl to press them all. However, individual Ctrl+key presses may benefit of the Right Ctrl key.

Multiple layouts for my native creates the need to engage in “mental modes” where your muscle memory tries to adapt to the layout you remember. I tend to configure the keyboard for the layout I use more frequently, even if it differs from the one printed in the keyboard. That makes for some confusing times for the rarer keys, though :)