I'm confused with the body part slots available in CS for use in making clothing/armor

I basically knows at least this much:
Upper body: waist up to neck, including arms
Lower body: legs
Hands: self-explanatory...
Feet: self-explanatory...
Amulet: necklace...
Shield: self-explanatory...
Right/Left Ring: very self-explanatory

Right, so I know these much, but what about the others? I'm talking about:

Head : what difference is it with "Hair"? Does that mean it basically replaces my hair?
Hair: what difference is it with "head"? Does that mean this doesn't remove my hair?
Weapon: now this... this is very odd... I thought we're making a clothing here?
Side weapon: ditto above, is this the slot occupied by sheathed one-handed weapon?
Back weapon: is this the slot occupied by sheathed two-handed weapons?
Torch: I thought a torch occupies left hand? so why the option? does that mean I can put something instead of torch and a torch is considered a clothing?
Quiver: is this the slot occupied by quivers? Does that mean I can make something using this slot and it replaces a quiver when equipped?
Tail: what about this? If I make something that occupies "tail", does that mean my Khajiit/Argonian will lose the tail and become more human?

Head: Removes the whole head. I think the hair and ears will stay, but if you have the head slot selected you want to have the hair slot selected as well. Otherwise it will most likely look silly. Head and hair slots combined are used for closed helmets, like the Daedric helmet.

Hair: Removes the hair and the ears, but nothing else. Used for open helmets, like the steel helmet.

Tail: Yes, this will make the tail disappear if you put something in the slot and the tail would normally be visible. Often used by modders from the fashion department as a 'free' slot for additional equipment, like hats, beards, nipble rings and whatever comes to your mind.

Not sure about the others, I don't think they're used in the game. I guess if you use them the equipment in the slot will vanish if you equip the armor that uses them. But I'm not sure, never tried.

Thanks! Well, that clears it up. I always wonder why the hell would a helmet occupy a hair slot while there's that head slot right there. I thought "hair" slot means the object will be put on top of your hair like an ornament...

I tried using the Quiver slot for my hair ornament and well... while it is equipped I don't see my equipment anywhere. Might make a good free slot for non-archers if it is usable

A quick question: if I have a clothing and the model covers upper and lower while in CS I assign it to only lower, does that mean I can literally equip an upper-only armor along with the clothing?

Yep - though it may look a bit off.