FME Desktop / and or Server should use default python installation, so that all existing packages and or fmeobjects should be in the same python interpreter.
I think the use C:WindowsSysWOW64python27.dll is not a very good implemetation (due to various installation of python).
During installation of FME Desktop / Server it should be able to detect python installations (if none install a python interpreter), and then setup accordingly. so the custom / default python should be combined
With this you then can choose between for example 2.7 32-bit and 3.4/3.5 64-bit etc.

