> The rendered output is determined by the Output File format and selected template properties.

Not entirely. Your project properties affect the final output. PA cannot assume that the current project properties are the ones that you want to use to render your files. Here is the scenario that PA is trying to avoid by prompting you for the project properties:

Let's say your default project properties in Vegas are set to 4:3 DV. You open Vegas, tell PA to render a bunch of HD widescreen files to DV Widescreen. If PA simply loaded the files and rendered them, each HD widescreen file would get loaded into the DV project and letterboxed. Then PA would render to DV Widescreen and Vegas will Pillarbox the Letterboxed media creating a postage stamp sized video with black bars on all sides. This is probably not what you wanted but this is how the project settings affect the rendered output.

Now let's say your default project is HD but the files you are processing with PA are DV Widescreen. If PA didn't ask you what project properties to use for the render, the DV footage would be brought into an HD project and upscaled only to be downscaled for rendering. This will probably be a quality hit not to mention the aspect ratios for DV Widescreen and HD 16:9 are slightly different.

This is why PA asks you what project setting you want to use. It's because PA is automating the adding of the media to a project and it wants to make sure that it uses the correct project size. It just doesn't assume that you remembered to set your project properties correctly before batch processing. It is better to ask, then to process for hours only to find that the rendered files were incorrect because they were brought in with the wrong project settings.

~jr