The Faithsabre says No! A blade which can only hurt monsters, and which Harry had had no trouble with previous, wounded him.

It burned him, he immediately snapped out of the state he was in.  Kind of a slap on the ass to bring him back.. Burned him a little, yes, but hey it could have taken his arm clean off if he were really bad in his heart. Harry felt shame and remorse every time he felt that pain, a monster wouldn't feel anything.

Nick needed Hannah Ascher for a specific job, and he needed Lasciel to take out Harry.

I think Lasciel wanted to take out Harry and Hannah with her grudge against Harry was the perfect fit..

I think Cassius was a wizard, but a minor one. Harry is gaining in strength all the time, even if it is still there it may get shed in time. The same way Cowl was contemptuous of Harry's death curse, and Kumori told Harry he has shaken off worse.

I don't think so,  think Namshiel was the only one.  Since Cowl never killed Harry, he never actually received it, easy to laugh off a threat.  But Harry was a lot younger then, he has gained in more ways that one, including deciding on the kind of death curse he'd throw and take into consideration who is killing him.  Not unlike his mother, she didn't just throw a death curse for the sake of it, she considered who would kill her and how best to get to him... And she succeeded..  I don't think Cowl would blow off a death curse from Harry now.

  Finding out what Thomas's motivation was, doesn't necessarily follow that he will be healed. 

You forget Harry has plot armour is a Starborn and appears to shrug off all forms of predestination - entropy curses, death curses, prophecy all have tried and failed. He is the ultimate champion of free will which means he is the White God’s chosen pain in the ass.

It’s telling that the Gatekeeper has trouble telling futures for Harry, the scene where he defies the White Council on Demonreach leaves the Gatekeeper confused that it’s too early in his timeline, and that he can’t win until Harry does something so incredibly stupid which is the epitome of free will in deciding to bind Demonreach.

A couple of things, being star born or not, predestined or not, what Harry's father told him still holds true.  If we die, any of us, we pass through that door alone.

Rashid had no problem seeing his future in Turn Coat, he gave him the odds of surviving against the Senior Council as low off the island, and a lot higher on the island and especially when he realized what Harry did.  I think there are rules that go along with having the eye that Rashid has.  I think it is the eye of the Three Fates, and rule number one is you cannot go around telling anyone what their future is going to be, because there are consequences for doing that, serious ones.

Maggie and Bonnie are both still alive. Still uncertain if the curse attached itself to Harry's penis. Susan and Murphy are both dead. Luccio and Elaine still seem to be alive. Lara is an unknown quantity for now.

And there are a whole lot of other people in Harry's circle.  I have to run down the exact quote, I think it is in Dead Beat.  It is when Harry dreams or has a vision of meeting up with his Dad by a camp fire.  That's when Malcolm told him not to be overly alarmed by that curse, because everyone walks though death's door alone.

Here is the quote I was looking for from Dead Beat page 420 paper back version

"Harry." my dad said, and his voice was very gentle, "can I tell you something?"
"Sure."
He walked around the grave and put his hand on my shoulder.
"Son.  Everyone does alone.  That's what it is.  It's a door.  It's one
person wide.  When you go through it, you do it alone."  His fingers
squeezed me tight.  "But it doesn't mean you've got to be alone before you go
through the door.  And believe me, you aren't alone on the other side."

So what I think Malcolm was trying to tell Harry, as long as he has friends, he won't be alone as he walks through life.  That is true unless Harry succeeds in alienating everyone he knows.  And when he does walk through that door alone, there are a lot of loved ones waiting for him on the other side. 

  However it wasn't much of a curse.  As Malcolm pointed out to Harry in his dream," everyone dies alone."  Also both Molly and Michael are very much alive, so is Thomas last we checked.

The technical term is “the Ringo”.

Or a "Hard Day's Night.."