In other wards you want a thief/rogue line of skills. Sounds interesting to me I don't see how lockpicking would work with the current claims system though. Hiding/sneaking totally sounds fun. Pickpockets were always fun to run after in Ultima Online. Maybe add them in as a general skill instead of a line of new skills.

after I gave it some more thoughts I want to explain how I think these skills would fit best into the game.

sneaking:
While being sneaky all your action should be quieter equal to your skill.
You should be slower but having the 100 perk of being able to run while sneaking (since it's possible but needs a lot of practice)
Should be needed to hunt effective, since you wont be able to find animals if you run around in scalearmor.

lockpicking:
You should be able to open claimed houses and warehouses but the higher the buildingquality the harder it should be and the longer it should take.
Also a minigame would be nice, but it's hard to find something good.

pickpocketing:
Should be able to do this even in claimed regions.
Maybe a synergy with sneaking.
With 100 you should be able to make a key of a lock (maybe if you got smithing on a higher skill) but it should only be used once and be destroyed afterwards.

eavesdropping:
I think it would be nice to combine this with a visual effect.
You would need to activate it and wont be able to do most of the other actions (crafting etc.)
You should see the local chat at longer range, maybe even doubled by current ranges.
The visual effect should be there if you activate the skill and show you the direction of people who make sounds around you.
With 100 you should get a sound or also something visual even if you dont activate the skill but with a lower range, just because you are caucious and attentive.

demolition:
You should be able to destroy doors but not gates.

I've been thinking well poisoning quite allot, maybe that could work :P