[Advice needed] Directory website on wordpress

I have a file of ~20,000 entries pertaining to a specific business niche in the UK with information like business name, website, email, address etc. I want to make a directory website of my own. I have purchased the listify theme and have customised it and set it all up ready to receive the entries. However I have some questions.

1) Each entry is inserted as a wordpress page. Do I need to take any security measures like saving these entries on a different part of my hosting or something, I'm a relative beginner to this field. Do I need to do anything to do with php or mysql or something? Or is it okay to just insert the entries as pages which the listify theme takes care of.

2) Do I need to be aware of any other security measures?

2) Can wordpress handle ~20,000 pages?

3) How do I prevent other people scraping my website with tools like scrapebox?

Any other advice would be appreciated. Thanks.

Ya handling of pages depend on server not wordpress. you can list unlimited entries.
You should purchase some security plugins for secure your data or site.

Also does anyone know where the accounts of users are stored by woocommerce on wordpress? How are they secured?