Brit,
Sorry to hear about your not-so-good day. :banghead: And welcome to the world of 'over torqueing' . . . . Anyone turning wrenches at this level has been there . . . . Ask me how I know? :jester:
As for welding the bung to the water pump, have you considered using J.B. Weld. I promise you, it will not leak once set, and you will have to pretty much destroy the bung/water pump to separate the two. I've used this product for many years with a ZERO failure rate.
Grab the family and take them to see Disney's 'Alexander and the Terrible, Horrible, No Good, Very Bad Day' . . . . . Your day will seem tame.
. . . . . :cheers: