When subscribing to the newsletter, I collect your name and email address. This is only used for sending you newsletters.
When paying for the newsletter, Stripe ends up with your payment details, and whatever other information you give Stripe. I don't use this for anything apart from receiving payments from you. If you sign up for coaching, I will use your Stripe account to send you an invoice. I do not automatically use your payment methods in Stripe, I invoice instead so that you have control over the payment instrument used.
My site itself does not currently use analytics. I used to have analytics, but I decided I wasn't using it much. If I'm gathering data, and not using it, why gather it?
Ghost records click information for logged-in users (User A clicked on Article B, and then clicked on Link C), which gives me some basic usage information. I rarely look at that, for two major reasons. Reason A - To understand at an aggregate level if my content is working (literally, and metaphorically). Reason B - When someone says, "Hey Dave, I can't log in!" - I go and look at whatever information Ghost records to help figure things out.