I think you've just got too many "okay next" steps. Also, is account activation really necessary? Couldn't I just start using the app immediately and activate within X days?
So our login flow requires email login to authorise because we also allow you to sync your data across multiple devices (if you choose to do so).
It's true that the signup could be simpler but then I'd worry in the case that someone uses someone else's email, that the real owner of the email when logging in would get access to the original user's session if they chose to sync.
Maybe we could have a more complex solution given some time. Any ideas?
Regarding the login flow, would you use Google Sign-In if we had it?