re: 3 - It may be true that google has a white paper describing the impact of api speed on retention. But beware, your users will need to have experienced this pain themselves, not theoretically, for them to be interested. They will need to have identified that latency (or churn - what is the actual problem you’re solving for users, that their api is slow out that they have churn?) is a problem that they want to solve right this second.

Make the value proposition extremely clear, and try to really help the user focus on a pain they have right now and that you can solve it.