Carousel News

How can more than 3 items (articles) be displayed in the Carousel News shipped with Sportal?

There is no limitation unless you set something wrong.

You use category to load articles from (if like on our demo) you need to put new articles in that category. Also there is parameter "How menu articles to take" make sure you did not put just 3. And Also there is parameter Show featured articles is its checked home page articles will be omitted, check that also.

I was looking at the JavaScripts and see that there is a default of 5 and sorting orders. How are these things changed?

In joomla admin, in module manager you can find module , enter its settings and change them. You don't need to alter javascript or any other code.