Woocommerce expert

Hi. I am looking for woocommerse expert to start improving in my website. At this time I need help with a few tasks and in future, there are more work which I hope we can cooperate,
1- in product categories there is a filter option for in stock and on sales. On sales working fine but in stock doesn't work. Even the product on backorder still listed. Can we fix the problem then can we change the name from in stock to Fast delivery. Also once I click either of filters the item per page change to 12 item par page. Can we have a set of 50 products per page in all the time.
2- The second work is can you please check for security of website. Make sure I have regular back-ups and no one can hack the website easily.
3- New delivery setting. Please check the new delivery chart below. (make sure the custom coded popup message is working depends on delivery location. Items on backorder and order weight. )

PLEASE CHECK THE ATTACHED FILE.

Thanks for your time.