For your request with schedule post listings :
1) You can refer to this snippet from our documentation that allows you to choose how many post that you want to show on manage schedule post so if you select 500 here it will show 500 post on that page and you will be able to select all and delete all togather.
– Link : https://docs.wpwebelite.com/social-auto-poster/social-auto-poster-snippets/#How_can_I_display_more_number_of_results_on_manage_schedule_page
2) For this implementation we might need to wait for more votes on this idea, for now the posts that are not published on schedule gets re-scheduled for next interval. If you need this to be added instantly you can take it upto our support team by email and they will assist you further.
– Email : email@example.com