A transitional modifier would not necessarily require a comma of any kind if it is at the very end of a sentence, although this is very much up to the will of the author.
Answer:
Hey there!
Samuel should introduce himself first, then state where he is from. A better introduction would be, "Hello, this is Samuel from Leah's Software Repair."
Let me know if this helps :)
I would say that he is selfish.
Jerry isn't grateful for that nickel the narrator gave him as he believes it is not enough given that everybody else gave more. He is acting rude and inconsiderate and doesn't think about the fact that the narrator may not have more money.
The answer is to identify the supporting details.
