It would kind of have to be like that, seeing as the cowl in Oblvion had enchantments that you cannot use in Skyrim, namely Detect life (unless there is a detect life enchantment in Skyrim?)

The properties of the Daedric artifacts change with every game. The lore justification for this is that the Daedric princes are capricious, and constantly change them. So as long as the powers you give it are very similar to (or at least consistent with) the ones it had in Oblivion, it should be OK.

BTW, I think I remember a demo video showing Detect Life in Skyrim.

Stealing from the poor, or stealing from the rich... Is there really any debate there? Can you think of any reason even the most immoral, selfish thief would prefer stealing rags from a poor man over stealing silks and gems from the rich?

I repeat, the Thieves' Guild in Cyrodiil may have acted with more kindness to the poor, but it wasn't necessarily because they were nice people. It was good business; it made their territory defensible and cost them almost nothing. We never have any indication that any of the Gray Foxes chose this path because they felt all sorry for the poor. There certainly weren't any handouts from the Thieves' Guild to the poor, except for one quest that in my opinion was more about showing the guards that the Waterfront was off-limits to them, and reminding the Waterfront that the Thieves' Guild was their friendly big brother until they tried informing. And the Fox himself never moralized, never told us that we weren't stealing from the poor or killing because those things were wrong. He never explained his reasons, but people thrust "Robin Hood" labels on him because it's a romantic and sympathetic stereotype.

Really, if the Thieves' Guild in Skyrim is going to go all softhearted, the player is perfectly capable of steering the guild that way without some creepy mask-wearing southlander getting preachy about it. Having someone undergo a "change of heart" because a stranger nattered judgmentally at them is poor character development, in my opinion. If we need moralizing, there are already people in Riften who like to moralize. If we need negative consequences for evil actions, these can be engineered. If we need positive reasons for change, there can be someone in Riften the player wants to impress, or to protect. Or maybe the player was always a nice guy working with bad circumstances, whatever his reasons, and he just starts making changes for the better the moment he has real power. Bring the old Gray Fox into it if you wish, but as I say, be ready with a whopper of a justification, both for his presence and for the player going along with what he says.

My character joined the Thieves' Guild with the explicit plan that he would rise to prominence and destroy the Black-Briars. He's a lawless, smooth-talking, selfish rogue with no objections to ill-earned coin, but he has a powerful distaste for crime lords who keep whole cities in fear, just as much as he hates jarls who do the same. It hardly matters where the rules come from, they are all thjizzrini, foolish concepts. As a Khajiit, he's fond of sweets in general and moon sugar in particular, but his life experience has left no doubt in his mind that skooma is a life-destroying drug that is especially dangerous to his own people; he destroys dealers wherever he finds them. On top of all that, he likes to be liked; it's not essential, but he'll convince people he's their friend, when they let him. He has reasons to steer the Thieves' Guild towards a more benevolent dictatorship of Riften. Imperfectly consistent, maybe, but I didn't try to sell him as a story for every other character to follow.

Simple, add a 2nd act to the thieves guild quests. I'd like to see a 2nd act put on the dark brotherhood as well.

I have a story idea in my head for a thieves guild quest line as well. I'll write it up!

I was actually thinking of doing the same mod! It seems entirely doable. But like others stated, it's a mask that creates a persona, rather than an actual person. At any rate, little will get done until they release the CK. Was extremely disappointed that it (the Mask) was left out. Just watch though, spend a TON of hours perfecting it and making the mod only to see it made by Bethesda as DLC

Thieves guild turf war with gray fox thieves guild and Assassin turf war for the Civil War Assassination contracts between Morag Tong remnants and the Dark Brotherhood. You can choose either side for both. That would be an amazing mod if done right.

Enchantments can change, almost every artifact's enchantments have changed from game to game. Besides, there is a Detect Life-like effect in the form of a shout, so I'd imagine there's a way to enchant something with it.

This was my favourite part of the the previous rendition of the theives guild, the whole "grey fox" persona gave this a lot of immersion factor to that quest line.
It would of been a perfect way to end the theives guild quest line in skyrim.
The final quest to hunt down the mask and would of been the way you as new leader brought a new life to the guild here in skyrim.