Since it doesn't stop a channeller from using the source, it would be an extremely nifty toy for a Forsaken, especially perhaps Demandred, who doesn't seem to like getting in the field where it's messy and dangerous... A weavebreaker would offer a bit of security.

For the rest, I agree the episode felt unnatural for WOT. It didn't respect the establish POV conventions.

I don't really have an opinion if RJ included a mention or the gateway or not. Maybe he didn't. If he already knew all too well how he would kill the gholam, he may not have felt the need to write it down.

I'm guessing he probably did, though. Perhaps not in the notes or outlines, but I'd be surprised he didn't narrate this episode to his family, and these narrated episodes have been transcribed and noted down. IMO, however, if RJ's resolution included a Gateway, I'd be surprised it wasn't supposed to kill the gholam has he passed through. It's also possible RJ noted down a few ways in which it's possible to kill a gholam, and Brandon picked the one he thought fit best.

It had been theorized it could happen this way - the debate was about how a channeller would manage to force a gholam through one, how it could be confused or overwhelmed and failed to sense the threat.