Yes they can be reduced, but you have to think of the tree as a complex system where all the parts have to work together to get you smaller leaves and shorter internodes.
(1) The fig needs to be in a bonsai pot to restrain its roots. If the fig is in early development, and is planted in a large grow pot, it will push big leaves and long internodes.
(2) The more ramification, the better. If a fig has only a handful of buds, they will grow more strongly than if the same fig had 4x as many buds (but still the same root mass).
(3) Yes, defoliation will help. However it is a short term fix that will only work if (1) and (2) are already met. Defoliate a fig in an Anderson grow flat with only a handful of branches and few buds, and your leaves will still be large.