That looks a brilliant idea Odysseus, and has the additional benefit in that if you do find water, on the basis that it will settle out at the bottom of the tank, you will already have a line in to the right place so that it can be sucked out without needing to empty the whole tank.
Out of curiosity in photo 130512, what purpose did the short horizontal section of pipe serve which you later converted to the present system? On my Bav 36 I don't have the same set up, so that making a connection into the fuel tank is one that I hesitate to do as diesel fuel has a habit of finding anywhere at all from where it can then leak. Even from places where it was impossible, it will leak, and as a result it makes an excellent penetrating oil for those times when the WD40 is anywhere other than where you need it most.
