THis is a funny question! I would probably say "Hello, thank you for showing your courage and coming in" to certain type of person, and "Hello, Welcome Home" to another type of person. Yeah, you know who I'm talking about!!!!
I'd say! "Hello! How did my life amount to this?!"
or I'd say...
"Welcome to Wal-Mart! They only give me 30 hours a week, so..no health benefits. If you don't see me next time, it'll mean I had a minor health problem, and became homeless. Then I'll be sleeping in my car in the Wal-Mart parking lot! Enjoy your cheap shiht from China!"
Well...I would say exactly what you're supposed to say "Hello, Welcome to Wal-Mart." and give them a wave and a smile. I'm pretty sure what you want to say would get you fired.