the greeting... well you can see for yourself

when you get into fights if you read the box it should say something different every time

:\ not alot of ppl read the boxes though lol... and some just keep it at the default not bothering to customize

. So yeah, I guess your answer is yeah it works!

thanks for customizing for the benefit of those who read the boxes

.
The farewell message I'm not sure though... I gotta check it out. I think it only works when you win but (ie you'll only see it when you lose.. which makes no sense cuz... you're dead :/ but it makes more sense than to hear it when youre OPPONENT's dead

).
The Banker's Guild isn't a guild that you can exclusively belong to... it's not like your guild of friends

you don't get a real choice of exclusive guilds like Elder Scrolls 3: Morrowind. It's just a club you can join for a fee via the character -> bank page.