When I say move the images to get the space back, I mean move them entirely off server to a backup location. The server obviously can't display hosted images that aren't on the server at all anymore.
Yes it can, so long as your "backup location" is accessible from the internet.
For example, let's say that your images are hosted at intosanctuary.com/media. This can point to any any static IP. Even if you move it from one IP to another, that'll change at the DNS level and the end result is unchanged for the end user. What that url maps to behind the scenes is irrelevant.
It doesn't matter if your images aren't on "
the server", it only matters that your images are on "
a server". You just have to make sure that the url points at wherever the files currently are.
If it gets to the point where you're running out of space and need to move a bunch of images to make room for a large file, then buy more space. If you can't manage to solve a relatively simple problem like this, then I don't ever want to see you bragging about how good this site's software is, or what great features we have, ever again.
If everyone just uses an external image hoster though, we can avoid this issue entirely.
The issue isn't being avoided, it's just being passed on to someone else.
They still have to keep track of the files, and if
they take down the content, as in the Peodophilia Ted talk, or in the million of broken imageshack or photobucket dead links I'm sure you've seen floating around, then the result is a broken link on the forums, which is the problem you said that you wanted to avoid.
So now, if we want to post an image or a video, we're now held to the free-speech-restricting rules and whims of youtube, imgur, etc.
Now, what I WOULD like to do is to have some easy way to upload images to an external site using just the XF editor, but those are paid solutions.
If you have access to create your own widgets with javascript/php, then this can easily be done. I've done this several times for work. We'd still be beholden to another company's rules, but the scripting of such a client-side api-driven upload solution is easy.