Lots of interesting points here - I guess you can argue the toss either way as to whether it's literally 'soul trapping' or 'magic essence', but I don't know if I personally can accept that in my mind.

What happens to human souls when they die - does everyone go to the Soul Cairn, or is that a specific punishment, say for evil deeds? And if you were to instead capture their soul in a black soul gem then they wouldn't go to the Soul Cairn. Is that right?

You only go to the Soul Cairn if you get trapped in a black soul gem otherwise it's off to the Dreamsleeve to be recycled except for the hand full of individuals that end up in Sovngarde or other realms.

Hope that helps

Enchanting is a magical art along the lines of necromancy, it's not technically "evil" but it's not something a good mage would be interested in, especially black souls.

I know you 'headcanon' it but I just want to point out that there's a couple of cows in the Soul Cairn and they're certainly not evil nor is Saint Jiub who also found himself trapped there.

Draugr haves souls, they're trapped in their bodies because they served Alduin and the dragons.

I always thought those that end up in the Soul Carin are there because they were trapped with Black Soul Gems. And it fits my headcanon perfectly.

Claudia (spellsword dragonborn) doesn't carry around black soul gems around to avoid sending some one to Soul Cairn "accidentally", but she has an ongoing practical joke with them necromancers in this regard. She makes sure to take as many black soul gems as she can when going to a (psycho) necromancer's lair... They are not a fan
As for other souls.. Well so much crazy stuff happens in the grand scale in Mundus that she basically doesn't give a damn about some lesser souls.
That's also pretty much her stance on her rather cruel nature (I checked, 90 days passed the start and 900 man/mer killed by her ! ), after all they will get recycled anyway and she rather be the hunter than the hunted.

Well Mundus works on very different terms as the Heaven/Hell model. After something dies it will go to somewhere in Aetherius based on their beliefs, or Daedra Oblivion if they are servants or out of Aetherious and into Dreamsleeve to be recycled.
http://www.uesp.net/wiki/Lore:Aetherius

From what I remember, the identity is stripped from the soul?


Not quite sure.

But ESO's (please don't kill me) enchanting might work, although it still uses souls to recharge the enchantment afterbthe initial charge wears off.

Essenrially, you use three different types of energy-imbued runestones to create a singular glyph; Aspect, Potency and Essence. This could translate easily into the single player games. Aspect determines the quality, Potency the modifier and base level, Essence the thing it affects. So I guess in skyrim equivalent, Aspect = type of soul gem used and Potency+Essence = the enchantment, sort of. Instead of having Absorb Health, Lower Health and Increase Health essence runes, you just have a Health Essence rune. The Potency Rune then applies the rest (in ESO also determines the level range of it, but for the SP games that can be ignored and the enchanting level used to scale it): Raise, Lower, Absorb, etc.
Doesn't use souls to make them. And seems like a more literal tske on enCHANTing

ha well headcanon is headcanon so I can't debate it with you....I have a few headcanon TES theories in my head too.

I just revisited Feyfolken. That's a great example. Thanks for its mention

...now I sorely want to go back and develop actual personalities for my enchanted items

That's a terrible thought... imagine having something around your neck with Don Rickles' personality... or a sword like "Barney"!

"I love you,

You love me,

(swish)

You're as headless as you can be..."

No, there are other animals in the Soul Cairn. I recall seeing cows there, too.

There's a farmer herding about 5 cows on some remote part of the Soul Cairn. I guess a necromancer got a bit too carried away at some farm on Tamriel.

Nope

Nope again

Enchanting was and is praticed by a lot of mages in TES and if you read some books :One of the best was Galerion .Well ESO made him against it despite him inventing means to do it even better than anything else .:

What is evil is to use black souls for it.

Draugr are not cursed they are either tomb guardians,Animated dead draugr aka Zombies or as is case of the Dragon Cult draugr willingly undead :http://www.uesp.net/wiki/Skyrim:Amongst_the_Draugr

You know what?I will do that too when I start playing again, but only with my most powerfull entchantments.