My mom bought me this tree 15 year ago off of a local bonsai grower. I thought it was cool, but never understood what bonsai really was. So it has been watered regularly and repotted once in that time span. I read now is a good time to prune ficus because the milky sap production is slow and it doesn't bleed as bad. I have no idea what to do with it though. I am still trying to learn all of the growing jargon. My wife likes it looking like a shade tree, Im ok with that, but don't care for how scraggly it looks. Any suggestions? I feel like the tree should be bigger, am I wrong?
Front:

Untitled by ptipton1, on Flickr
Back:

Untitled by ptipton1, on Flickr
Roots:

Untitled by ptipton1, on Flickr
Front:

Untitled by ptipton1, on Flickr
Back:

Untitled by ptipton1, on Flickr
Roots:

Untitled by ptipton1, on Flickr