Audacity has a scrubber tool, ctl-left click. drag across waveform, hear music. I personally also find it easier to set timing marks at full speed.
I showed my wife how to play the wave files at slower speeds, she prefers setting timing at full speed also. She is a musician also (violin and piano) , not sure if that helps her hear the timing clearer.
It would be nice for some folks if we had a scrubber, i dont know if any of our developers would need it. The priority of developers is usually for things that we can use in our shows.
The scrubber tool in Audacity is a little jerky when i tried it (Audacity 2.1.2)