Could bomb testing make the world fall apart or cause tsunamis?

I think it is very unlikely. The energy needed to cause something like a tsunami is huge, and to make the world fall apart it would need to be even bigger. It might be possible to cause a tsunami if a bomb was planted in a particular place and the Earth's plates moved. This would require considerable planning, so a tsunami shouldn't be caused by bomb testing, unless it was many times bigger than Hiroshima and Nagasaki.