Customer address in Welcome Email / get an admin email when changes to the account

Problem: Due to concern for credit card fraud, we've separated the "create account" process from the "order" process, so customers have to sign up and wait for manual authorization before they can place orders. We verify the information they have submitted and then approve (or not). But, after approval, we can't tell if they go in and change their information.

So - I want to include the customer's registered address in the Welcome email, preferably down in the "Office Use Only" section but anywhere is really fine - it's just for archive purpose. I've modified the email text verbiage & options in create_account.php but am not sure how to define and call the address, city, state, zip, & country fields.

Then, if possible, I'd like to have the system send an admin email when the customer changes any information such as name, billing address, email, etc. Ideally, the email would include the old and the new info. We use the membership management software aMember for a different part of the site which has that notification capability and it's proved helpful in our efforts to combat fraud.

These are probably 2 separate issues/processes but all tied to the same concern of maintaining historical info on the customer accounts.

Thanks for any help & insight.

Current version of ZC 1.5.7 - site was set up in 2010 and periodically updated using the procedures outlined in the instructions.
Currently on PHP Version 7.4.33, will update when I do my next ZC update.
Have made fairly extensive verbiage changes throughout using the template process (new versions of the pages are kept in template child subdirectories)

But, after approval, we can't tell if they go in and change their information.

You could make the pages

index.php?main_page=address_book_process
index.php?main_page=address_book

Throw errors and not permit changes (tell them to email you any address changes, for example).

Then be sure to set the max number of allowed addresses to 1.

https://docs.zen-cart.com/user/admin_pages/configuration/configuration_maximumvalues/#address_book_entries

Max number of addresses is set to 1 currently. The challenge with them not being able to update their own billing address is if they are trying to place an order at 10am UK time, I am fast asleep on the west coast of the US, so they would have to wait - and we already make them wait for account approval. I'll look at those pages, though, thank you.

You'll lose sales but you'll also have less fraud. You have to decide the right balance.