The vast majority of phones shipping today include VP8 in hardware. VP9 is a bit rarer at the moment.
While it's up to you and your lawyer to decide whether you can ship a codec, many companies feel perfectly comfortable shipping VP8 and VP9, including Mozilla, Google, Samsung, most SoC vendors, etc.
Wrong. Using VP8/VP9 means you have to accept the Google license, which says it is void as soon as you claim software patents are invalid or sue in court against any of Google’s claims.
And VP8/VP9 has again the same patent issues as h264.