What flags you when buying/selling gold?

[hafrakaka]

Hey guys,

Checked the forum and found a somewhat similary thread from 2007 but still only answers one small question and it's probably outdated.

What methods does blizzard use to flag currency exchanges in the game (i.e. between a goldfarmer and a gold vendors or vendors and buyers)?
There are three main ways to transfer currency between players; face2face, mail and through the auction house. I've read some news and old forum posts and I want to ask you pro's if this correct and if some of you could elaborate more if you have the time.

1) Is face2face the most secure way? Is it true that Blizzard can only monitor f2f transactions manually? Is there a gold limit in your bag that raises red flags for blizzard?
2) Does blizzard have an automated systems that monitors all mail transactions and if a transaction is above some value it raises flags?
3) Are auction hause transactions the safest way?
4) Does blizzard monitor chat (even private chat) for strings like "gold" "buy" "$" and such in the same sentence?
5) Any other tips you guys have?

-Hafrakaka