Saving by nick is a very low priority for me, since it's insecure and the only people that really want it are those running non-steam servers. And I don't support non-steam servers neither does amxx obviously because it is not legal but more so for the reasons Bail stated
here. I would have no idea the problems you get from running it, nor would I want to bother trying to figure them out. There's a whole discussion going on about non-steam that should even be there in AMX Mod X 1.8.1 Released post.
SH saves by steam id, if no steam id or on lan it will automatically save by IP. That is all for now.