Playback functions are all controlled from the transport.

Hit the fast forward, fast reverse, reverse play, and forward play to hear what shuttling is like. The frame advance buttons are only useful for video. The audio is rendered in realtime at normal speed before it is stretched or condensed, so slow systems may drop samples.

Once you've mastered the transport, you can try out the keyboard equivalents:

spacebar -> start/pause forward playback
k -> stop playback

The number pad with numlock off is much more powerful than the mouse:

4 -> single frame reverse
5 -> 1/2 speed reverse playback
6 -> normal speed reverse playback
+ -> fast reverse playback
1 -> single frame forward
2 -> 1/2 speed forward playback
3 -> normal speed forward playback
Enter -> fast forward playback
0 -> Stop

Pressing any button or key twice pauses it. Likewise, pressing space pauses and resumes the currently active direction.

For point and click operations, the speed of the fast forward and fast reverse buttons can be toggled by going to Settings->Slow Shuttle. On a fast system with Broadcast 2000's transport, you'll be very good at scanning CD rips for jitter and scratches.