On the delivery issue ...
We've been Costco Exec members for many years, and one benefit was the check we received at the end of each year. We don't shop at Costco as much as we used to, so that benefit may not be worth the higher membership fee.
We have 2 Costco warehouses within 30 minutes radius but, on a few occasions, Chris has ordered from costco.com, typically bulk paper products. The delivery/shipping fee in each case was $0. I have no idea if that's a perk of exec membership.
On one occasion, a friend asked Chris to check if something was available online, and that resulted in a $6 delivery fee to the friend's house. Haven't figured out if that was because of a different shipping address, although the friend lives several miles closer to one of the two warehouses and the third one mentioned below.
In each case, our deliveries are fullfilled by a 3rd warehouse, approx an hour away. IIRC I saw a Costco delivery van outside our house on one occasion as I arrived home.