i have one correction to make!
the water in the seal wil never boil!
your cooking a water-alc mixture, the boiling point is below 100 degr.
the water just evaporates, the hotter it is, the faster it evaporates.
i think routing the coolingwater through the sealing might give problems.
when i top-up the level with some water (+- 50-75cc) the still stops dripping for aprox. 10-15 seconds.
this is becourse you are cooling the top off the boiler and the hood.
at that moment you have some reflux, your "steam" condenses at those cold spots.
to avoid this fill whith hot water.
in my opinion the best thing to do is add a litlle oil to the water so the seal is sealed to avoid evaporation.

sealing a seal?
or yuse oil instead of water.
but whats the problem off topping up once and a while?
when running your still you should be around, so no big deal!