You can certainly attach USB drives to the VM via the ESXi host. I do this for a few VM's every week to send some data off-site. It's a small amount of data so it works fine for my purposes.
Your server probably does not have USB 3.0, and even if it has USB 2.0 you will not get anywhere near the max speeds. The speeds I've seen are usually around 40-60 mbps.
In other words, there's no way you'll be able to transfer 1.5TB in <8 hours across USB.