As for the "don't leave unattended," one thing you could do is charge your batteries in a fire proof container, such as a flower pot, old military ammo can, cassarole dish, etc... This will make sure that if something does go horribly wrong while you are charging a battery that you will not lose your house or anything like that. This really is not much of a concern for NiCd or NIMH batteries because they are really stable. But if you wanted to put your mind at ease, a fire proof container would be good to charge your batteries in.

When I am charging, I just plug them in and forget about them basically, unless it is a LiPo. But with your batteries, I would not be too worried about something bad happening.