Very interesting build and one which I will definitely be attempting in the future!
Love playing Teemo; ever since I first picked him up a month or so ago. Wonderful balance of annoyance to the other team, damage that persists and wards that pack a punch. One thing I could suggest is in the placement of shrooms; I find it useful to think about where I would run to if I was on low health and wanted to port back. If you manage to find yourself in enemy territory these are the places shrooms are best for a sneaky kill.