If something is on the leading edge, it is using the most advanced technology available.
Usually followed by the word "but," this is essentially a call to pay attention to the next words out of the speaker's mouth, e.g., "Not for nothing, but did you see the way he looked at you?"
If you bleed someone dry, you extract all their available money from them.
If you let the dust settle, or wait till the dust settles, you wait until things have become calmer or have returned to normality after conflict or a problem.
Diversity is essential- the world would be incomplete if everyone were alike.('It takes all sorts to make a world' is also used.)
If something like an idea or system takes root, it becomes established, accepted or believed.
If someone comes very close to dying but live, they have a brush with death.
If you bring something home, you explain it or make it very clear.
Something that is lightning fast is very fast indeed.
If you up stakes, you get ready to leave a place.