Must have missed some things...

Tapping on the windows...........That would be the "knocker-upper" who was employed by whichever company the person in the household worked for (as in coal mining or the shipyards etc) & who would come around in the early hours of the morning & tap on the bedroom windows with his long stick thereby waking the workers up & getting them out of bed to start their work day.
Remember this was the 1930's & very few people had alarm clocks then but then of course with the "knocker-upper" around you didn't need one anyway!
I do wonder who or what woke the "knocker-upper" so he could start his day though..........

jewsih guy askingfor money: I think he was a landlord.

father arrested: doesnt seem like. remember he disappeared when the jewish family was taking the burned daughter to the hospital, so we can assume the authorities never knew who did it. (but the family did, because we see how the all react when he gets back home).