Does export without "render" = lower quality?

Unless it is necessary leave background rendering off.

This will not degrade your final Share/Export destination.

As already mentioned, it may speed up an export but rendering takes an equivalent amount of time plus it uses your disc space.

Al

it will render when you export

It might speed up your exports to render in the project, but it's not necessary

It doesn’t generate render files on export. It processes into the assigned format and codec directly.