Since willow leaf ficus back bud so easily, and you can chop them back hard, I would plant this tree in a much larger growout container and let it grow for a couple years. In the late spring, when temps are above 55 degrees, move it outside until the fall. I do this with mine, and I get the best growth outdoors. The sun will keep the leaves small and the branching dense. With a poly tent or good humidity, you can get some great air roots growing. Feed your ficus well and dont move it around, and it will grow quickly.
Once you are happy with the trunk thickness, you can chop it back and basically put the branches where you want them.
I have noticed that when I move mine back indoors for the fall and winter, it will go through a leaf drop and not really grow much at all until it goes back outdoors in late spring. But I do not use artificial lighting indoors, which I may change this winter. I do have numerous metal halide and T5 flourescent fixtures laying around. Anyways, my best advice is to let it grow unrestrained for at least 1 year, better for 2 years. Then you will have more to work with.
