Being able to serve your website from a CDN helps the customer: it means the website is up when they want to visit it, and it usually means it's faster for them.
Having static content not get cookies helps the customer: it keeps HTTP traffic down, which means that pages load faster.
Separating cookies between different websites helps the customer: it means that when, inevitably, blog.example.com gets broken into, the customer's account info at www.example.com is not compromised. (Of course, this assumes that you're doing least-privilege between your various websites, but you're already doing that because you care about your customer and don't want to send them a letter about how you lost their personal information.)
Not using a separate top-level domain for static content helps the customer: they know that www.example.com and static.example.com are from the same company they trust, Example Industries, Inc. If you caused their browser to show that it's loading files from "static.excdn.com" or something, they might worry.
The customer isn't personally following the redirect; their browser does, so I'm not sure I understand how the redirect deprioritizes the user. As far as visual clutter goes, get an EV cert, which either supplants or replaces the address bar with something much more useful than a URL:
Being able to serve your website from a CDN helps the customer: it means the website is up when they want to visit it, and it usually means it's faster for them.
Having static content not get cookies helps the customer: it keeps HTTP traffic down, which means that pages load faster.
Separating cookies between different websites helps the customer: it means that when, inevitably, blog.example.com gets broken into, the customer's account info at www.example.com is not compromised. (Of course, this assumes that you're doing least-privilege between your various websites, but you're already doing that because you care about your customer and don't want to send them a letter about how you lost their personal information.)
Not using a separate top-level domain for static content helps the customer: they know that www.example.com and static.example.com are from the same company they trust, Example Industries, Inc. If you caused their browser to show that it's loading files from "static.excdn.com" or something, they might worry.
The customer isn't personally following the redirect; their browser does, so I'm not sure I understand how the redirect deprioritizes the user. As far as visual clutter goes, get an EV cert, which either supplants or replaces the address bar with something much more useful than a URL:
https://www.expeditedssl.com/assets/browser-ssl/extended-val...