One problem with hosted analytics that keeps getting more obvious recently is that adblockers automatically block the domain names of those trackers. I think hosted might still work, but you would have to offer custom domain names or find a way to avoid adblockers.
Also, what does end-to-end encryption mean? HTTPS already does that, right? If there's some extra encryption on top, does it mean that the client will encrypt the analytics data before sending it?
That sounds interesting, but it feels like the whole purpose is to hide the data from your company. How can you make sure that you don't have access in any way to the data, if you also store the user accounts that have access to this data? If you wanted, what would stop you from logging in as that user and viewing his data?