Hi rado.

I try to use ngons when exporting the LWO. MoI export really nice, clean and "small" meshes.

It depends on the model and how dense I export, but usually I delete the vertex and UV maps. Some model I get is big and messy so it looks really bad with the vertex maps.
I do clean up the model so it looks nice with a smoothing angle of 10-20% in modo. The Merge tool and Merge in modo is great to "fix" the model.

See images below. This model was modeled in MoI and exported as LWO and rendered in modo, with and without (first image) vertex map. As you can see, keeping the vertex map usually is a good idea. :)

Hope that helps. Feel free to ask more questions. :)
-J.O.