Hey there, yes the kit will give you a great start on your project. Let me know if you have any trouble with the purchasing system.
This code, which runs on the robot (RasPi), is open and available here. You are correct, it receives commands from the server via socket io.
https://github.com/runmyrobot/runmyrobot
As for the server, you can use our site with privacy if you want. The privacy feature is brand new, so you can't see it in the interface yet, but it's there. We just have to turn it on. Or, you can build your own server/webclient if you want. We can provide all information you need for messaging protocol and such that's used to move the robot.
Let me know if you have any questions
Best!
Rick Giuly rgiuly@gmail.com Co-founder RunMyRobot