Enjoy, although quite a sad chapter this time.
Heart and Pulse are already broken: Doesn't seem to be an idiom. I think this is a somewhat ancient way to say someone is sure to die. You can think of it as the regular beating of the heart and pulse being broken and erratic.
Widows and orphans: Yes he would've been a half-orphan but I don't think anyone on their death bed is really thinking about specifics.
Wandering through the world once, not a loss: Translates literally as 'World above walk a round, not a loss.' It's not an idiom but from my interpretation, you can think of it in two ways. It could mean that he's travelled a lot around the world and as such, his life has been worth it. It could also refer to how living a life upon the Earth in itself has been worth it in the end. That he had found enough value in it at the end despite his rough early life.
This immortal: Less of a translation note but A-Ting hasn't really referred to herself in third person before. I think she does it here because of how Zheng Liu asked her to give blessings as an immortal. It must've affected her as while she is so much stronger than mortals now, she's still relatively powerless overall.
I was a little surprised how sad I was with his death. I guess it's because he was the strongest mortal tie that A-Ting still had, she doesn't have many left anymore.