Surely you must be
When in red, I was very loud.
In high definition, a treasure.
You put me in to interfere.
Rest on me for your leisure.
Put me between the last two letters,
I am an Asian plant.
Keep some of me in the water,
And being unsettled you can't.
Title: "Sometimes with Feathers?"
You are an:
My prefix causes bells, whistles, and dings.
My suffix is done by all living things.
My infix causes all empires to untangle.
My whole, they tend to dangle.
As for the title, I am not entirely sure but:
I think the answer is
My prefix led a talk to beat a killer from within.
My infix works for former bandit, shooting with their twin.
My suffix can be found in range of anime-like weapon.
My whole, while very powerless, caught peaceful man's attention.