that would depend on if you have listed three or more nouns , pronouns before it. if it is exactly three, it doesn't matter.
last comma before the and is not necessary
Do you put a comma after the last name of a P.A. e.g. Jan Farinato, P.A. or Jan Farinato P.A.
Yes, you should use a comma before "Jr." when writing a person's name to separate the person's last name from the suffix. For example, "John Smith, Jr."
Not necessarily. Only use a comma when the final please is a request. For example, we say Do as you please; but Sit down, please.
before
You can use ", and" or just "and" but not just a comma.
No, a comma is not necessary.
You would use a comma before it. Xerox, Inc.
no
If it is the last word in the sentence than yes you would use the comma. Commas are so you could take a little rest between words. Examples: I like cotton candy, too! Your at this park, too? I can't believe you did this to me, too! You gossip, too?
if the main or most important part is before the main parts you use a comma, but if it is after then no comma
Yes, you can put a comma before except. Example of a comma before except in a sentence- She can do it, except that the mountain is too steep