I had a funny feeling about the grounding issue. Weirdbits or DrNomis might be able to explain it. I have no EE background, but my understanding is that buzz is often the result of your unsheilded parts acting sort of like an antenna. That is particularly an issue with pickups. You ground the bridge primarily to ground the strings. Perhaps the strings act as sort of a shield for the pickups? In any case, glad to hear that the buzz went away ;-)

Any solder job that works is a good one IMHO. Also, good call attending to the toddler ;-)