I've been touch typing for years, and none of my fingers have experienced any strain, or ever been overworked. In fact, the reason I learned how to touch type was to _reduce_ the strain on all my fingers.
Interesting, I touch type okay enough but don't use the pinky for symbols/ENTER. I use the ring finger of my right hand for symbols/ENTER and and the pinky for just the shift while pressing symbols with middle/index finger. I use pinky on my left heavily though, I wonder if it's a sign of anything (unbalanced typing?).
If you use some symbols very often it makes sense to put them somewhere more accessible. For me { is Alt+j and } is Alt+k, [ and ] are a row above. Creating a custom keyboard layout is very simple.
