Thank you for contacting us.

For questions 1, building this requires some pro features and some core features. www.remarpro.com rules state that commercial products are not supported here and therefore I cannot guide you for these products.

Buttons can be linked to specific pages or anchors. You can learn more about that here:
Anchor Widget

For questions 3 and 4, here you would actually need to add custom CSS code to enable these features.

For question 5, you can certainly do that by following these instructions:
Back to top button – Elementor

This article also may be interesting for you to read as well:
how-to-create-sticky-sidebar-menu.

Thank you.

Regards,

Gil