how do I switch option + f to [next word] instead of ƒ
All those shortcuts you mention work with control+_. So either you can remap your option key to behave as control, or make yourself habitual of using control.

https://support.apple.com/en-us/HT201236


Swap CMD and Alt only on external keyboard 
How do I remap a key in macOS Sierra, e.g., Right Alt to Right Control?