Does anyone know any tips or techniques for reducing the imported model down to a more useful geometry for Unity? I've also been trying to optimize it in Maya, but haven't been able to find a command option that successfully reduces the model without crunching into a useless form.
This mesh looks typical of a 'Boolean" operation victim. While the triangle count isn't outrageous you would get a cleaner model using a shell modifier and maintaining quads rather than a Boolean which results in those ugly triangles.
If you mean the selected wireframe in the image, it looks fairly optimised; certainly enough for it not to impact performance. I wouldn't worry about it, unless there is anything specific that's concerning you?
edit: in regards to optimising geometry, I would always recommend using your 3d modelling program rather than Unity.
I'd do something like this:
And, yes, there are a lot of ways to retopologize your model. Try to search "retopology in /your 3d package of choise/". As far as I know there good tools for this in 3ds max, maya, zbrash. There is even a programm which is created solely for this purpose - to retopologize, the programm is called Topogun.