If you’re looking to export multiple images organized into folders while preserving the folder structure, there’s a plugin that can add that capability to Lightroom.
Lightroom Plugins by Jeffrey Friedl
Here’s a method for exporting square photos from Lightroom without having to create virtual copies or use the crop tool.
The Lightroom export function allows you fine tune the quality of the resulting JPEGs in increments of single percentage points. But it turns out that the quality settings actually work in bands.