I never said all 3 of you had the same IP, I said the IPs that were used to login to your characters at the time of this happening are IPs that have already logged in to your characters prior to it happening (say literally since you guys started playing them)
The sharing passwords is irrelevant, if you've played any other private servers, you shouldn't be using the same password here. There's too many private servers that do NOT hash your password (and can thus read your actual password).
The person who went on to the aGelmirVARDAMIR account (who emptied your clan bank) didn't trade any items to anyone; He either burned them, disassembled them, or flat out deleted them.
Hope to see you guys again, and in future - please, use the provided methods to secure your accounts to avoid situations like this.