Ok, I've seen the idea of redirecting a Waaagh at our chaotic neighbors repeatedly pop up, and it's a neat idea, but the idea always seems aimed at the same target, so I have to ask why Amir-Ka? I mean looking at our lists of neighboring and regional powers and Amir-Ka would not be my first or even second or third choice. Amir-Ka is neither the closest Chaos power to us or even the strongest, and it's history of being internally focused on it's own politics makes it much less likely to launch a serious crusade against us then the more traditional chaos polities also neighboring us(sure we might get the occasional raid by an internal faction like Atlas, but we can handle that easily enough).
Comparatively, The Princedom of Demagoye is a mere 110 lightyears from us, and is a fully Slaneeshi Domain. Meaning that once Vect's deal goes through, it's going to get uplifted to a tech level higher then us sooner rather then later, so I'd ranking taking it out before that happens a higher priority then any of the others.
Then there's the Princedom of Assour, which at 400 light years is just as far away as Amir-Ka, but is even bigger and is the largest and most powerful neighboring Chaos power to us. And as they are a traditional chaos power under a single Chaos Lord, I'd easily rank them as a much larger threat then Amir-Ka.
Pass them, is the More'lumix's Realm, which at 500 light years is the furthest away but is a fully Tzeenchian Realm, which again makes them more likely to attack us do to Tzeentch's paranoid fear of us accidently screwing with something the Old Ones left and blowing up the galaxy.
I'd honestly rate Amir-Ka as being more around the level of the Nexx when it comes to their threat level towards us simply because of how distracted their internal politics leaves them.
