Can I use wildcards in events?
Not in Socket.IO directly, but check out this plugin by Hao-kang Den. It provides a Socket.IO middleware to deal with wildcards.
Prevent flooding from single connection?
Limit number of events by
socket.id with rate-limiter-flexible package.
Socket.IO with Apache Cordova?
Take a look at this tutorial.
Socket.IO on iOS?
Take a look at socket.io-client-swift.
Socket.IO on Android?
Take a look at socket.io-client.java.
Usage with express-session
Please check this guide.