Compiling a list of all personal data currently located in your systems and making sure you have a legal basis for each item, goes a long way towards compliance (though of course this is not all you need to do)
- WooCommerce on url xxx: phone number, email,name & address. Google Analytics & facebook Pixel. Requirement for e-commerce fullfillment and analysing website performance / ad performance.
- Mailchimp : email and name, when accepting WooCommerce "Terms and conditions" n°2. Requirement for recurring ecommerce updates/changes of new products.
- OpenERP: ( invoicing - local network) - Firstname, lastname, address, email, phone, orders. Requirement for invoicing
Somehow i can't believe that would be sufficient.
With Mailchimp you probably need to let your customers separately opt into their e-mail being used for marketing purposes, as again that use is not strictly required to fulfil their order.
Same with any other information - your customers need to be aware of all the ways you will use their data. If any uses are not covered by a legal agreement, there needs to be an option to opt-in.
I really doubt most small-medium businesses without ties to the EU are going to pay any attention. Just like VAT actually.