My main question is what happens if he stops running the server? is the whole project dead then? What will be his incentive longterm to keep running the server? Is it just based on altruism?
Yes, in this stage Webcash is just an experiment. If the main dev (who owns/runs the server) will stop running it, the project will be dead.
Everything else you can discuss on the Discord server! We are discussing there in which direction the project could go.
One big topic is how to built or who want to built an Webcash exchange. Another big topic is, if the amount of Webcash token should be increased.