That's quite a statement, and totally wrong. While it's been known for a long time that Google ignores the
keyword meta tag, they place quite a lot of importance on the page title and description metatags, and also look at others. See
Meta tags that Google understands and
Google's Search Engine Optimization Starter Guide.
Almost - Google have said they will use mobile-friendliness as a ranking signal, so mobile friendly websites may rank higher on searches conducted from mobile devices. If and by how much is anybody's guess - I've even seen tests indicating that there's no real change (yet!). More info -
Finding more mobile-friendly search results &
FAQs about the April 21st mobile-friendly update.
As for Google Plus pages - I wouldn't personally place much importance on them. Google Plus is being gradually picked apart, and the latest update makes it (IMHO) largely unusable, especially from a business POV. Much more important (again, IMHO) is to verify your business with Google (
https://www.google.com/business/), which covers searches across Search, Maps and G+.
That's nothing new, they've pretty much always done that and anyone trying to manipulate things with "black hat" techniques (think low contrast / invisible text, duplicate content etc.) totally deserves what they get - see
Webmaster Guidelines.