1. I see a graffiti painter.
2. (Widać tylko jedną osobę więc dlaczego "they"? Ale dobra, niech będzie, że "they".)
Near the wall. I don't know exactly where. Maybe under a bridge, or near a cemetery because they often have big walls.
3. The're painting a graffiti.
4. In most cases graffitis are small and ugly, sometimes vulglar. I think such cases are pure vandalism. It should be forbidden and graffitis should be removed. On the other hand, in some cases a graffiti can be really beautiful and add a lot of taste to a nearby landscape. Sometimes graffiti painters are paid to make such graffiti. These can be even called an art, I would allow to let them stay untouched.
