So the island is the source of the leylines and provided the energy for the denarians to create the greater circle to contain Ivy. I would hazard a guess then that it provided the power for Merlin to set down spells/enchantments to create Demonreach. We know from another quote in Cold Days that the energy that keeps people away is the body heat put off by the prisoners. I wonder if it also has tainted the leylines/well. Rashid warned Harry not to touch the leylines. Was it because it was too much power for him to handle or potentially corrupting due to the prisoners?

  If I remember correctly, Rashid added that Harry isn't ready to control that kind of power yet.  I take that to mean at some point Harry maybe ready to control or use the leylines, but he has to either mature more or gain more skill to do so at this point.  Whether it corrupts him or not to do so remains an open question.  It is my belief that Kemmler did use the leylines in his quest to bring back the dead.  It is also possible that doing so corrupted him.

I don't recall Lara ever spelling that out in a plain-talk manner, something that was unambiguously a suggestion/offer.

She has spent her whole life (a couple of centuries at minimum) working the flirt-and-tempt angle.  Even if she meant it seriously, I think she'd couch it in flirt-and-tempt ways (and, consequently, Harry would always see it as a predator's lure).

I simply don't have the time to research it at the moment, but it is clearly implied from the get go.  If you think about it Lara has all the qualities that Harry wants and loves in a woman, only drawback is she is an unapologetic vampire, he is aware of that also at all times.   

I'd looked there, it's not spelled out.  Maybe I'm mis-remembering?

It isn't spelled out but it is sure implied.

  I think it was in White Night, towards the end.

I am suggesting -- as a WAG -- that in the future we will see Murphy get back onscreen via a "convenient" combination of loopholes in the "rules," and conflicts over which "rules" apply in her specific case, and some degree of being "misled" (which gives Uriel just a touch more leeway to act) and her own rebelliousness over "following the rules" vs. "doing the right thing."

All of it, largely, orchestrated by Uriel (who exceeds even Mab for subtlety).

Maybe, but Murphy chose to break the rules, no one pushed her to do so.  She chose to proclaim that she believed she had the right to judge Nic over the Almighty and got a Holy Sword broken in the process.  She demonstrated an arrogance akin to one of the Fallen.  None of that was orchestrated by Uriel, wouldn't be.  This is stuff she took upon herself.  I think the best that could be done for her was to let her go to Valhalla and become an Einherjar, one of Odin's warriors.  She may be back in Mirrormirror, and possibly Harry will figure out a way to being her back to his dimension, but she will not be the same.  That's the wisdom of the rule, it's a kindness not a punishment.  Actually I have a WAG of my own, there will be a moment when Harry will have to chose.  He can only bring one back to his dimension, the choice will be Murphy or Chandler.  At the end of the day, Harry knows that his Murphy is dead, this isn't the same Murphy, she belongs in that dimension, and Chandler was snatched from his dimension and trapped in one where he doesn't belong.  Harry knows what is right and he will do the right thing, he will leave Murphy, painful as that is, and restore Chandler to the dimension he belongs in.

Remember that in Ghost Story, Uriel intentionally misleads Harry, enabled because one of the Fallen had previously misled him

Uriel was only able to intervene because Lasciel lied to Harry pushing him to suicide.  Otherwise I don't believe he would have been allowed to, I believe Uriel says as much.  I would have to go back and read, but I think Uriel says that was the only reason why.

If my WAG is correct, Gard/Vadderung is similarly "misleading" Murphy into joining as an Einherjar, in part by implying a more-passive / less-engaged role with the "White God."  The "rules" that Murphy is led to break are Odin's rules.  Obviously, my WAG may be wildly off-base!

However I don't think you can say that Murphy was misled, she was well acquainted with the Einherjar a long time before she died.

We'll have to see how Jim writes it, of course.

But no:  just because someone "rejects" Heaven, it doesn't at all take things "out of Uriel's hands."  Maybe other angels don't engage, but... Uriel??!?

  Uriel is limited, he might be an archangel but his power is limited by very serious rules. 

Apprentice by definition;

a person who is learning a trade from a skilled employer, having agreed to work for a fixed period at low wages.
"

That wasn't Kim's relationship with Harry, she wasn't working for or with him, and it appears she was paying him very low wages [a steak because he was hungry] for knowledge so she could pass herself off as something she wasn't.  Because of his over active sense of taking responsiblity, Harry may have called her a sometime apprentice, but she wasn't.  There was no agreement between them, she did no work that we know of for him.

The odds are very good that -- though Dresden was undoubtedly overqualified to teach her -- he was still the only teacher who was qualified and willing.

No, he was the only one around that had the knowledge she wanted.  Harry started to answer her questions in payment for the steak, but when he realized what she was asking about and where it could lead, he was no longer willing to answer. 

Someone who pilots a fighter-jet can train a student to fly a commercial airliner (for many years, retired fighter pilots were the single largest source of commercial pilots for US airlines) -- they don't have to train them to be a fighter-jock.

You know it is a lot more complicated than that.  Also you didn't define "student," in your analogy, for some trades to become a student requires prerequisites. 

A "practitioner" would be the term, I believe.  He was teaching her to be a better (safer, more in-control) practitioner.  She clearly had enough power to get herself in trouble; I really can't see Harry refusing to train someone like that (particularly an attractive young woman).

Which doesn't make her his apprentice. He may have taught her some things, but he didn't train her, but she never was really a student of magic.  I can take a cooking class which would improve my cooking skills, but that doesn't make me a chef.