Damaging the stem is a result of applying pressure to the stem. How are you holding your hands? Obviously one is on the pump handle, but where do you position the other? A common technique is to brace the pump with that other hand and pump as if you were pushing your two hands together. This way the pressure is applied to the pump only and not the wheel or stem. The wheel will rock, but no pressure is being applied to the stem.
If you want completely effortless pumping and compactness try using CO2.