So if I model a mesh like this:

http://i.imgur.com/HSb3DBM.jpg

It exports the triangles out like this:

http://i.imgur.com/NKcdVYH.png

It creates a few unnecessary triangles.

I'd like it to be more like this:

http://i.imgur.com/KypTs3c.png

Notice how there are less unnecessary triangles by just altering the topology a little. This means less triangles for the renderer, as well as less triangles for any physics per triangle collision being done.

Is this something typically worth worrying about? I've never heard anyone mention this kind of thing when modeling static meshes. Are there any ways to make this automatically happen in 3DS max? I can probably manually detach vertices on some of the faces and ensure that 3DS max triangulates the faces how I'd want, but that may backfire later when I edit the mesh again and my topology is now all messed up.

That usually isn't a good idea, as you introduce T-junctions in your model. Each edge should only border exactly one other edge, and no vertices. When drawing the model the two lines won't always line up perfectly with interpolation and floating point inaccuracies so you can get artifacts at the edge.

Oh, OK. I found this article: http://wiki.ldraw.org/index.php?title=Avoiding_T-Junctions_in_LDraw_parts

I guess it shouldn't be a problem for 3D physics meshes though if I happen to use a triangle mesh of some sort for collision.