May I suggest that we keep it as clean as it now, and maybe have something like the domain `/advanced` for those who want more features? (If OP has time to implement them)
A big no no for me. Seen a couple of sites and never tried clicking. I'd rather use the 'sign in with google' button where I get to confirm rather this privacy insensitive method.
To disable this feature (at least for chrome 69, not sure if it will change), go to account-consistency: chrome://flags/#account-consistency and select disable.
Taxify already has a rider feature in Nairobi, Kenya, called Boda within their app. It's insanely cheap and the ability to circumvent traffic is a huge plus. I'm happy this is coming to Uber as well.