Hallo,

my current character tries to free slaves to get into the Twin Lamps faction but it's not an easy task.

He is an aspiring thief and exploring slaver caves can be a dangerous task for a low level character.

So he tries it in the Hlaalu and Telvanni cities, sneaking into houses to free those poor fellows.

The problem is he can't find the keys to free them, pickpocketing their master shows no result and even detect key does not work.

I would like to do it peacefully without killing anyone or using any workarounds – I have read if you don't have the key to a slaves bracer then take him to a zone where you own a bracers key and it will unlock the bracer – this would fit to a mage and not a thief and it breaks immersion to me.

I can't imagine taking slaves for a strider ride or buying hundreds command hummanoid scrolls.

The USPWiki shows all slave locations and probably the location of the keys too, but that would be cheating, I want to discover them for myself.

As I have lost dozens of hours to futile explorations, pickpocketing sneaking and turning every pillow around I would only like to know:

Does every slave bracer have a key that be found around or is it impossible to free the slaves without using command creature etc.?

Have I missed a way to free slaves? I look in caves, on plantages and in manors – plenty of slaves, no keys.

I have only found one NPC on the Dren plantage that owns a slave key, the Suran slave merchant has a key to the jail doors but not the bracer keys, the slavers in Tel Mora and Tel Arun must have lost their keys and the list goes on…

Any hints?

From what I recall, there are some slaves that cannot be freed. Or at least, not by Commanding them to a distant location.
The best way I found to free enough slaves to get the Twin Lamps missions is to ignore slaves in towns and plantations, and instead focus on rescuing slaves from the bandit/smuggler caves.
As you saw on the wiki, many slaves (and the keys) can be found in caves/dungeons. But if you don't want spoilers to know where they are, just start searching for caves
Although usually protected by at least one tough NPC, they are usually easy to rescue once you're at least lvl 10-15

Do you use mods? There are some mods that focus on the Twin Lamps, and add more content about freeing the slaves of Vvardenfell. (since the vanilla game doesn't touch on it very much)

Yes, I use Nevena's Twin Lamps and allready found some ingame additions from this mod. But as I'm not a member yet, I stay away from this quests.

I'm level 8 at the time and not a powerfull character, no idea if I can fight powerfull slavers…

This could be a good idea for a mod – adding keys to all that slave zones, giving them to NPCs or hiding them around.