1. Because it's decentralized, the complexity doesn't increase by having additional nodes on the network. The complexity does increase to a small degree as seen by your node as you make contacts. I guess my answer to your question is it's very scalable.
2. I have a notification loop that runs once every three seconds. The result is the latency is about 1.5s from when I send a message to when it shows up on my contact's phone.
3. Because it's a self hosted network, the data loss protection is up to the person running the node. I added a cron script to backup my node node once a day, but someone might want something more frequent...or less.
Very interesting. Have you considered the possibility of monetising encrypted backups? Allow people to backup their node on a cloud service you provide. Keep the data encrypted in a manner that only the owner can decrypt. This would give users mental peace, and could be a monetisation source for you.
That's a really interesting idea; I hadn't thought of that approach. My super long shot idea is that enough people would use app that a router company would be interested in licensing the node and app software and providing a self hosting solution for the common consumer.
1. How scalable is it?
2. What is the expected messaging latency?
3. Data loss protection?