Hi there,
1. you could use CSS Flexbox to re-order the content on mobile – like so:
@media (max-width: 768px) {
.site-content {
display: flex;
flex-direction: column-reverse;
}
.inside-left-sidebar {
margin-top: 0 !important;
}
}
2. The above CSS will place it fill width and no gap above on mobile. Let me know if thats what you mean.
3. Sections being a simple pagebuilder removes all theme elements from the content, but there is this PHP Filter to allow them to be displayed:
https://docs.generatepress.com/article/allow-sidebars-sections/