I've got one trading char which's used to sell blues and boe epics to the ah. Gold from selling goes back to my main. A 2nd low char is used as bank for the stuff often used to high level profession skills (fire, ice, water in their variations for example).

My chars have all professions and everyone stores the stuff used for his profession by itself. So my tailor holds all cloth, the green non soulbound things goes directly after every run to the enchanter and he stores the dissed stuff.

Gold is hold on all chars (I've only one team (5x80)). If one needs to buy anything and has not enough money, he gets it from the other chars. So it doesn't matter who has the gold actually in his bag. It's one team and all gold belongs to all chars. If one becomes more powerfull through buying something, the whole team becomes better.

Maybe I've to say that my team is in a raiding guild. I played in this guild solo for a long time, so they accept my team also when i'm not raiding anymore since I've started to box.