raskolnikov

I have a red maple myself. What I've found is that the leaves don't reduce very easily. Also, the internodes between leaves is longer than some other varieties of maple. However, I've decided that with mine I'm going to have it grow in the ground a bit and become a larger bonsai. This will allow those large leaves to look more in scale and believable.

For your tree, I'd probably chop off the trunk down to the lowest little branch. I think these trees are pretty resilient, and it can survive it. Keep that new leader trimmed pretty hard to try to encourage greater branching.

Also, I think I see your tree in a bonsai pot. I think common practice is to have a tre more developed before thinking about a real pot to put it in. Try a plastic tub or even a flower bed.