I can't see doing that either, as I always make a hard save just before ending a session. I don't make hard saves every 15 minutes, but then I'm rather fanatical about system maintenance; as a result it's very stable, so I don't have to worry about random crash-outs. I don't mind over-writing my auto-saves either, as I have a rule that I always stick with the decisions my character makes. I also make sure that I am not in the middle of a dungeon or multi-stage errand when I end a session, so if I put that character aside for a while I can pick up right where I left off without having to wonder if I'm forgetting something.

As for sorting my characters: I keep 5 hard saves per character (thinking of expanding that, though), so the breaks in the numerical sequence are where it changes characters. I also keep my very first save, which was made just before the character generation screen; this lets me start a new character without having to sit through the long cinematic each time. Named saves I reserve for a special purpose: I use them to denote the end of a character's career, since at that point I delete all other saves for that character so that his/her story is set and cannot be changed.