Hello,

1. & 2. Both plugins are well-optimized. It is not possible to tell exactly which one would be better since it depends on the project requirements and features that you will use from one or another plugin.

3. Elementor has its own feature to optimize CSS files delivery.

4. Of course, we don’t have plans to abandon WPBakery page builder support. All our future demo versions will be available on both builders.

Kind Regards