AFAIK only Samsung used a fingerprint scanner on screen and they've already ditched that... But yeah, I kind of get your point 
You mean on the Galaxy S5? That would have to be weighed in regarding data randomness obtained in both methods and if the security given by one method tops over the cost saving the other method offers.
I'd say generally, that the retina scan should provide better security however there are obviously important factors that play a role in this. I wonder how secure the iris scanner in the latest Galaxy Note is.Since it would only be to recover a passphrase, I'm not sure if it would be all that impractical (you would only use it once in a while). We would probably have to build hardware for that tho... Lips are very distinct, and they're also used for investigation in forensics, hence my idea 
Indeed. It is less impractical if rarely used, although I do wonder the implications of this. From what I've gathered, there's only some research in this area.Fingerprints aren't safe wallets since they are basically really easy to replicate even with simple household items.
This statement is incorrect. You may be able to pull decent fingerprints, but that is inadequate for one to bypass fingerprint security easily. People need to learn fingerprints are usernames, not passwords
Thanks for sharing the post. The author makes a very good point by stating that compromised fingerprints can not be changed (which is the exact opposite of passwords).