Admin approved file uploads I want to allow all authenticated users to upload files, but I want them to be approved first before they're publically viewable.  I'm currently using a single image field for the uploads, that can have unlimited values.

I'm not sure what is a good way of going about this.  Let's say, the user uploads 4 images, which are all shortly after approved.  Then, later, they upload one more image... I still want the first four to be publically viewable, but I don't want the fifth one to be until it's approved.

Also, I am kind of concerned about the fact that the files would be downloadable immediately, as soon as they are uploaded via sites/default/files.  Is this a big deal?  Concerned about copyright violations and such.
I believe what you wanted is similar to commerce file module where users can upload file and have configurable settings, where you can limit access duration, number of downloads etc. and about this one downloadable immediately, as soon as they uploaded via sites/default/files. Is this a big deal? yes it is big deal once you uploaded it in sites/default/files everyone can access it and download anytime without restriction you may violate some regulation. you should upload it outside Drupal where users can't access it via url. Where in commerce file already have this settings where you could place your file folder outside Drupal. I am not sure if this is already available in Drupal 8.