Pet peeve: "impacted" as a past tense verb. I heard it on the news again last night. "The company is unsure how its sales will be impacted by this incident." Uhmmm, I think the word you want is affected.

I don't mind "y'all" informally. "You" can be plural or singular. In Chicago I hear a lot of "you guys" or even "youse guys" - but again, that's informal. In a past position I had a manager who was from the South -- she would use y'all to address a small group and "all y'all" for a big group, like "all y'all go ahead and go home, the weather's really bad, but transfer the phones to the answering service before y'all leave.'