This sounds like the resource manager addon, which you can see in action here on this very forum as it is an official xenforo addon, see tab link to resources at topAwesome.
Another thing, which I did some searching around and it seems you need to buy an add-on for this feature. The ability to download software that's managed through the forums with the ability to add screenshots/images to the information page as well as different categories with categories within' categories.
Can users upload/add content to this system or is it only available by an administrator of the forums? If users can upload their own files what kind of management does the admin have over this?
You can change the URLs using the Route Filters option in the Admin CP. You can use the "Phrases" system to change phrases that contain the word "Resources" to "Downloads". Depending on how many phrases there are, this can be quite a labour intensive task, but it's one that you only need to do once.So the link(s) read as "Downloads" or something similar instead of "resources".
There are a few widget based and portal add-ons but they are third party resources available here: https://xenforo.com/community/resources/Is their any sort of "front page" type portal? Something that can show news articles, top downloads (resources) or new downloads (resources) and other similar format?
You can make resources require moderation, you have options to set allowed file types and/or extensions. There are also permissions regarding who can create resources, and who can view and/or download resources.Can users upload/add content to this system or is it only available by an administrator of the forums? If users can upload their own files what kind of management does the admin have over this?