You'll likely find as your animation progresses that you'll need to tweak the relative distance between key-frames.  To do so, you can simple click and drag on any key-frame in the time-line located at the bottom of your screen.  You can also hold the Cntrl key in order to be able to select multiple key frames so you can move them simultaneously.
It will also often be necessary to expand or reduce the total length of the animation. To do so you can simply left click in the second number box of the “current time” section of the time line.  This will allow you to not only type in a new total length for the animation, but will also present a check-box letting you either stretch the keys to maintain there relative positions to each other or not.  You can also preview your animation playing back at different speeds simply by adjusting the playback speed slider at the left side of the time-line.
Editing the Timing of Key-frames or the Entire Animation

Spriter Pro User’s Manual version 1.4