Are all the comma placements correct in the following direct addresses? I say yes. Do you agree? Victor said, "Thanks, Zach, Pete, Laurie, Joe, and Mike, for your continued support." (Also, is the comma needed after Mike?) Frank said, "Many thanks, Steve and Dave, for your dedication and commitment." (Comma after Dave?) Helen said, "Thanks, Mike." Julian said, "Thanks, Sam, for your continued diligence with the project." (Look okay?) Thank you.
Yes, I think these are all correct. As to the first one, Victor's speech, I'd certainly leave in the comma after 'Mike.' Read it out loud, as if you're making a speech at a presentation, and see where the pause comes. If you were standing and pointing at all of these people in turn, you would definitely pause after you say Mike's name. The comma indicates that pause.
I would omit the first comma from all three examples. I don't think you need commas after 'Thanks'. The rest are ok (including after 'Mike').
@jazzabel According to the Webster's Compact Writer's Guide - This doesn't seem to be an optional use of a comma. I checked a few other sources as well, and they all agree on this one. I'm afraid all the commas need to be there. It's easy to get distracted by the list of names in that first example, but the number of people being directly addressed doesn't affect the issue.
and a comma is definitely needed after 'thanks' when followed by whoever/whatever is being thanked... it wouldn't be, only if followed by something else, such as: thanks for coming thanks go to the group for their help thanks to your help, they now have a home
