There are three issues at play.
1) The hotlinking server's bandwidth: Since you own the servers and bandwidth, this isn't a problem.
2) Copyrights: If you own the relevant copyrights to those images, the images are public domain, are exempt through fair use, and/or you otherwise have permission, this isn't a problem. (It helps the mod team to indicate, as a caption to the hotlinked image, the general nature of the permission you're using if it isn't clear the image is your creation.)
3) Our users' bandwidth: We'll enforce a 100K limit for a single image, and less officially, we'll want you to keep from going too much over 250K per thread page. Many of our users have bandwidth restrictions of some sort or another. And so, as a courtesy, the more it's spread out, the less of a problem it'll be. (The one exception to this is the Astrophotography forum, where we generally won't enforce image size or quantity rules, within reason.)
In short, our preference is for you to link to the image with a short description, or use thumbnails, (so that 1. our users can opt-in, and 2. we don't need to worry about liability issues), but under the circumstances I've just listed, we'll allow hotlinks. Always within reason.
"Words that make questions may not be questions at all."
- Neil deGrasse Tyson, answering loaded question in ten words or less
at a 2010 talk MCed by Stephen Colbert.