frugal:
Some wrong information there.
Number one for instance, there's no proof that this is actually so. In the past, maybe yes. But not anymore. Google will show your site for those queries if you have a better content. We know good contents get shared and linked to a lot which is all Google needs to rank your website above others. Moreover you can geo-target your website using webmaster tools if you want to (still doesn't make much of a difference). The key is better content, social signals and making sure your website is properly optimized (no duplicate content issue, etc.)
I totally agree with you!
"Google will show your site for those queries if you have a better content" but still, .Ng domains will always outrank .Com domains on SERP provided you have a better content and you are targeting Nigeria.
Using a .Ng domain is like telling Google that the content of your website is basically for Nigerians.