Using separate domains with WP Multisite is a bit of a 'sledgehammer to crack an acorn' IMHO
You can definitely use WordPress Multisite to have separate domains on the same WordPress install - e.g. hockey.mysportssite.com, hockey.mysportssite.com etc.
But your more detailed description indicates to me you probably don't need the extra complexity of running separate WordPress sites to achieve what you are looking for.
Depends on your WordPress skills, but I would tackle the separation you are looking for using WordPress Categories. It's super easy to display lists of posts based on WordPress Categories.
To make the sections look different I would use some custom coding to add a custom surrounding class to each unique section which I can style using CSS.
While creating separate domains with WP Multisite using different themes is possible to give you what you want it's a bit of a 'sledgehammer to crack an acorn' IMHO.