1/2:  Npub.pro takes your Nostr notes and basically displays them as a themed website (you pick the theme). It says “Set up any tool for analytics, lead generation, monetization you desire” and has an icon for MailChimp and others, but I don’t know how that work - you can ask @brugeman about it - he’s building it and is great about answering questions. As far as I know, you can’t integrate with WordPress.

I do recommend you set up an npub.pro website and play with it, but I don’t think it will easily do all the things you want right now. You can see my npub.pro site here: https://rustypuppy.npub.pro - that’s the theme I picked. You can go to https://npub.pro, scroll down, and you’ll see the different theme options and example real sites. You can even preview your own content in the different themes to find the one you like. 

 Mailchimp and others can be integrated using code injections, i.e. if you want to collect emails for the newsletter.

"Wordpress integration" is a very broad idea, need more specifics about what exactly the needs are.

Selling digital products is definitely planned on npub.pro, there is already a nostr-standard for that, we just need to build support for it.