your first question is warranted and makes sense
............................
second one is , at best , rushed.
tip we consider cheap, often rightly so , may be assessed as generous or sufficient by the guy in question, specially if he did not have customers for week or two and rent is due or shoes are leaking.
I was witnessing Christian meeting "his ' boys by chance on the street or in the bars on quite a few occasions and never noticed any sign of contempt or displeasure.