kristos,
IF you can get your direct die cooler to mate up with the outer edges of the die and seal it there, you will probably not have problems.
If your direct die cooler has a larger opening than the die itself you will have problems as it HAS been stated the adheasive that holds the die in place has a problem with water over time.
As to your 2 component glue... If you get anything under 1 mega ohm across a 5mm spread of the glue on paper, I wouldn't use it. As to the waterproof aspect, you would have to check with the manufacturer's data on that.
The beep test on a meter by the way tests for Continuity or how low the resistance is across a circuit. This can be considered conductivity to a point. Usually meters "beep" at 400 ohms or less. This is quite a low resistance and simply tells you there is a DEFINITE circuit there, almost as if you have a regular wire in place.
Hope that helps...
