jobel , I am afraid that since Sprite animations are, in essence, just sequences of individual images, there isn't a way to blend frames from one animation to an other.
If you choose to go with cutout animation style however, Spriter supports animation blending and/or weighting.
With the default Sprite animation route, you could build a system with inbetweening animations from specific key poses/frames within an animation that will transition to other animations. However, if you want a "snappy" result, you'll have to use many, many transitional animations... It will be very hard and, depending on the frame number and size, system taxing endeavor.