Ok so first timer here. Played a bit and at lever 15, no issues thus far. My question is, how does robbing people and breaking into houses affect me in the long term. If I see something very valuable should I steal it and run?.

not sure. I did have hired thugs come after me for stealing when I thought I had gotten away scott free. they were the hardest fight in the game sofar.

I've had 3 Hired mercenary's come after me before. Only if you get caught does anything happen, if you get away without being caught, then they won't even know you did it.

Ok so I stand to make a lot of money and items breaking into people's houses at night?