Resource Manager, yep, just manages files. If your community members need to share and download various types of resources then it's great. If not, you don't need it. It's not built in, it's an additional cost, but it is developed by the XenForo devs.
Post Ratings is great if you want more than just the "Like" button. You can have various others either positive, negative or neutral. They can be whatever you like.
Xen Porta provides a front page and has been popular for some time. There are some other Portal add-ons and various add-ons and guides that will help you set up a home page. Search the Resource Manager for "portal".
It's a new site I will be starting. I currently own two VB license from past forums, but want to switch over to Xenforo.
BUT the site will focus on collectibles, so I know there will prob. be lots of images.
Other developer add-ons I recommend you look at are add-ons by @ExtraLicense @borbole @Waindigo (i'm sure there are others) but off the top of my head you'll be taken well care of by those and those I listed above.