Hello,
01. You can achieve that by using Custom Links in your menu and setting the URL to just #. This way, the main menu item won’t be clickable or lead anywhere.
Then, you can add your dropdown content (linked to your HTML blocks) as a mega menu under that custom link. This will display the dropdown properly without loading the HTML block when the top-level menu item is clicked.
02. Sorry to say there are no such options in theme settings for the menu item.
03. Navigate to Theme Settings > Product Archive > Products Grid. Under Shop Products View, select the “List” view.
Best Regards,