1. I can't think of a single case where the Angular documentation has failed me. Yes, it's sketchy in places, but what open source documentation isn't?
2. I'm not sure which toolchain you're referring to, but Angular is just a framework - you can use whichever toolchain you like. You can even use no toolchain if you wish.
3. Debugging has improved significantly since 1.0, especially since Angular started adding HTML comments to denote where markup is generated from. Browser extensions like AngularJS Batarang and ng-inspector help out as well.
4. Again, I don't know exactly what you're referring to here, but I feel like Angular's concepts and semantics fit in just fine with other systems. Scopes, services, controllers, modules... These all mean what you think they mean.
5. I'm genuinely interested how you think using an open-source JS framework will tie you to a corporation? Hell, I'm interested how using Java will tie you to (I assume) Oracle when things like OpenJDK exist?