On a true 5V pass-through, I strongly recommend NOT connecting through a USB port on a PC, use a separate 2A rated power supply; way too much potential for damage to the PC, and even if it "works", the odds are that it is over-drawing on the PC USB port, it's likely a voltage sag. The Madvapes 2A supply is fine, as is the IQ 2amp dual USB power supply, available from Walmart online.
No problem using a tank, you just need to have the atty or cartomizer rated as 2.5 or greater ohms, so the current draw stays under the 2 amps. I tend to like about 8 watts power, a 3 ohm cartomizer, though some particular eliquids can be nice at 10W, a 2.5 ohm carto/atty.