Finally I think I've done most of the fussing with my servers, and I actually backed up and turned off the server that was causing all the problems. It's work is now distributed among three servers. Seems likely that I'll have enough bandwidth.
And since the AFP app was unplugged by AFP, I now have the freedom to move that server. They were sending the pictures to a fixed IP address, if I ever moved it I would have lost the pics.
And a reduction of the number of concepts you have to master. Most of them are irrelevant vestiges of the way some engineer who's probably dead used to think about this stuff before anyone understood it.