Does that not mean that his or her free will was screwed with?  Harry chose to suicide based on the lies that Lasciel whispered in his ear.  Because he made his free choice based on her lies, Uriel was allowed to step in because since his choice was based on lies, it really wasn't a free choice.  I know, this stuff gives me a headache too...

No, actually, that one's easy. It's not the "his choice was based on a lie" that matters, it is "who told him the lie upon which he acted" that does. As long as the choice is made due to a Fallen's direct manipulation/involvement, Uriel gets to interfere (to the same extent as the Fallen did), due to the White God's stipulations. If Mab had told him the same thing Lasciel did, and Harry acted upon that the same way, Uriel wouldn't be able to do anything to stop it.

The *current* version of the Accords is from 1994.  The Accords are old enough that all the players have the rules pretty well figured out.  Plus, they're built on systems that are older, like guest rights.  It's like the last time a bunch of people got together like in Peace Talks to update the Accords was '94.

That's wrong, even the Dresden Files RPG says so:

"THE UNSEELIE ACCORDS

In 1994, factions from the Nevernever went to open battle with each other in Milwaukee, Wisconsin. Such things had happened before, of course, but mankind had a new tool for sharing information rapidly and globally: the internet. With the advent of the Digital Age, Queen Mab recognized the need for improved security and discretion and acted accordingly—and swiftly—to end the conflict in Milwaukee and limit the potential for future outbreaks of violence. The result of this action from the Queen of Air and Darkness was the Unseelie Accords, signed by those same warring factions. Mab’s influence and will are not to be underestimated."

And the WoJ seems to be (the source I have for it does not mention where the original WoJ is from):

"How old are the Unseelie Accords? They are Mab's accords, and she hasn't been in charge forever, after all. "
The Accords are fairly recent: they were signed when Dresden was a young man, before he went independent as a detective.
If I was writing it all again, I'd probably make them something happening early in the series. Chicago would have belonged to the White Council and been their dumping ground for problem wizards--the ones who weren't quite bad enough to kill, but who had to have an eye kept on them. Harry could have conflicted with the genuine bad-guys-in-process, emotionally saved maybe Mort Lindquist (who would have been one of them) and probably screwed up hard enough for the White Council to lose Chicago, making it essentially open territory, like Casablanca."

Also, Proven Guilty states this:

"There’s a sign Mac’s got hanging up at the door that reads ACCORDED NEUTRAL GROUND. It means that the place was supposed to be a no-combat zone, under the terms laid out in the Unseelie Accords, the most recent and influential set of principles agreed upon by most of the various nations of the supernatural maybe ten or twelve years ago."

IMHO, if there *was* something equivalent to the Accords before 1994, it clearly didn't include anything which gave Eb (or the WCouncil in general) any grounds against the WCourt.

I believe the intent is more along the way of a security camera system, where you can have as many cameras as you want, but you are limited by the amount of screens and terminals at your disposal, to watch and operate them live.
So I think there can be an unlimited amount of infected individuals, but Nemesis can actively control or manifest through only 13 or so of them at a given time.
I would also argue that this limit is per universe/dimension/timeline as well, because otherwise having such a tiny limit would practically make Nemesis impotent, since we know there are hundreds of thousands of universes if not millions or more, due to every "major" decision from a ("important?") mortal creating a separate one.