Is there a way to make a figure "soft?" I have heard of soft body physics but don't know if it is something that can be done in Daz studio 4.9. So let's say I wanted to make a persons gut sink in when another figure hits them. How would I do that?

There isn't a n automated way as such, though you could try applying a Smoothing Modifier to the victim of the punch and setting the collision target to the puncher. You could also use a DForm, or a Push Modifier with a weight map (via Create>New Push Modifier Weight Node), but those require manual set-up.

I have heard of weight maps but never used them. is there a good tutorial on them you would recommend?