The "drinking a few" part is fine, but you don't want to leave your pot unattended anyway because of one simple fact. BOILOVERS!
Keep it supervised, make sure to stir to avoid scorching, and keep the regulaor monitored & a spray mister handy to avoid boil overs. If you must leave it unattended, make it for only a very brief minute. Boilovers sneak up quick. I have only had a small partial boilover, i got it under control very quickly. The clean up was not fun. It peeled the paint off of my garage floor.
As for brewing on your wood balcony, I would suggest going to the local Home Depot, or Lowes. You can grab a couple of 12"x12" paving tiles, or cinder blocks, or brick, for fairly cheap. Instant homemade hearth!!!