You should probably mention that the PT requires a powered USB port (rated at 1000 ma).
Some laptops either do not support this, or support this over 2 ports (so you cannot have a PT and charger in at same time) or only support this while plugged into the mains.
Also, it should probably be mentioned that you can get a) portable usb batteries to give you a walk around PT, and that you can get wall-socket USB converters (however most don't meet the 1000 ma requirement)
Also for refilling:
The white cap can be removed with a small gague crochet hook, a bent paperclip, a handle off a bulldog clip, or any similar tool. So long as it can fit into the breathing hole, and hook in. Apply steady pressure while rotating the cart, increasing the pressure until the plastic end cap pops out. Be careful not to pike the removal hook in too far, as you can accidentally hook the atomizer wire (with drastic results).