I would cut the center one out rather than untangle it. Three branches originating from the same place on a maple branch is usually one too many.

If I leave it as is, will the branches continue to grow healthy?

Very cool. Will possibly grow together, which is also very cool. I have seen this before. Really can't hurt anything, as trees are tough. They are just two branches, and as this is a shrub type maple, strength of the limbs is not a problem. Don't over worry.

I also think it is quite interesting looking, so I'll leave it as is.

Another question on caring for this tree...If I want this tree to continue to grow upward, do I need stake the leader? How do I exactly do that? Or will the tree do that naturally on its own? It appears to be a mature tree, it did not have any stake when I purchased it.