You say multiple IPs, then you say you only have 2 computers
So if each computer has an IP assigned, do you have separate links to the internet for each computer? or do they perhaps go via the exact same router that will NAT your connections behind the SINGLE ip address provided by your ISP.
So we establish that you did most likely have 16 wow sessions coming from the same internet IP address, but then you could say well hang on.. i was using this proxy software, what the hell is the point.. you'll just have 16 accounts appearing to come from the same proxy IP address, if its commonly used proxy then blizzard would likely flag that as even more suspicious. This is even before you start considering that they might have another identifying feature of the machine as a point of reference, like the MAC address of the NIC, system ID from the bios, or even a unique client ID that they generate and store in a file on the machine just like an internet cookie (or like the crap in C:\Users\All Users\Blizzard Entertainment\Battle.net)
All of the above points to someone coming here and screaming banwave because they are totally clueless to the possibilities that exist, I'm sorry that you lost 16 accounts but you have clearly jumped to the first conclusion either without thought or without intelligence, your efforts to protect yourself sound grossly misinformed and ineffective and so we come back to the fact that you had 16 accounts online simoultaniously for 10hrs a day, likely racking up reports from real users and the fact that you were botting becomes pretty much obvious to whichever GM looked into them