将定制的CMS数据库转移到Wordpress - 我需要考虑什么?

I've been tasked with taking a Bespoke CMS and making it into a Wordpress site. The current bespoke database for "news" is quite basic and covers only one table.

A PHP script will draw the current data, sanitize and format it ready to be INSERTed into the Wordpress database. 16000+ articles are not going to be cut and pasted!

So far I have only covered data for the wp_posts table - how does wp_posts_meta relate to wp_posts?

Are there any other "gotchas" I need to consider?

There is also data that could be construed as "pages", so do I just treat that in the same way?

I have previously built scripts to transfer from one bespoke to another bespoke site, and have lots of experience in Wordpress - I don't need PHP or MySQL advice, just never had to work too deeply with a WP database before and not sure how tables relate.