Best practices i've noticed have been to have each bot on a seperate IP and don't directly trade the items and or currency to the mule, that way you leave a digital trail.
party with a couple of your own characters preferably more than just you and the mule, drop and have the mule pick it up.
Don't friend your own bots to one another and dont friend your mule.
Never bot on your mules IP.
Don't get lazy and slip up, get the IP's mixed up per bot could lead to multiban. Be smart, don't do 24hour botting sessions try to keep it looking semi human
make sure to ocassionally talk in global or trade chat, get known just a little bit but keep friends to a bare minimum.
Be smart, don't be lazy about it.
Q: How often do bans occur? A: Whenever they feel like it
Q: Are they for the 1 account? A: Not always
Q: Are they IP bans, Mac bans, or just account bans? A: IP and account I believe
Q: Are they permanent bans? A: I'm not sure that all cases lead to permanent bans
Q: And would it be safe to dump profits into my guilds guild bank? A: I would not think it would be safe.