User blog comment:The Milkman/Indoctrination Theorists Say the Darndest Things/@comment-3469974-20121021084225/@comment-4237253-20121021225453

1. You can read here and here that destroying a mass relay causes an explosion, not just an asteroid. If it's destroyed, it causes an explosion. It's why BioWare changed the dialogue; they were fixing a mistake.

Also, here's a quote from the article:

2. You can have adequate manpower for the Crucible but still be lacking in other areas. You could say that less ships would mean that the Crucible could get damaged, but that's just speculation since we don't really see it take any damage.