A few questions about pickpocketing your own drugs.

[Robonator]

If you pickpocket your own addicting drugs back from a client, do they still get addicted? Does it lower their satisfaction? Does it lower their loyalty?

If you fail a pickpocket and your client attacks you / calls cops / runs away, does this lower their satisfaction/loyalty?

[I C DEAD PEOPLE]

Naturally they won't be happy if you fail. Loyal and happy customers are better way to go. I haven't even done it for the achievement.

There is also a chance an addicted customer will knife you :D

[di eshor ribly]

There are a couple factors:

Did you sell 1 baggie and steal it back? The customer didn't smoke it, no addiction. Their satisfaction and loyalty come from the deal itself, not the drugs. So those don't change.
Did you sell 4 baggies and steal 3 back after letting them puff the first one? Their addiction changes.

I haven't noticed any reputation losses from failed pickpocketing or beating up customers, but I have noticed it if you sell them anything with 'Explosive' on it. I don't bother with stealing much though, there's enough money in running a drug business as it is without sticking my hands down Cranky Frank's tighty whities.