Sorry how are keyup/keydown events not event-driven software?
Ironically 5 minutes before I read this I changed a coworkers POC 3d app to use event polling instead of key events as it was horribly unresponsive.
Stick with a PS/2 keyboard, it makes it easier to spot malware using the USB bus https://wiki.wireshark.org/CaptureSetup/USB
Which is event-driven architecture. A component signals that something happened and other components take in that information and update their local state as appropriate.
Yes, that's right. We're talking about EDA, not CQRS or the like. EDA events signal a change of state from one component for other components to synchronize on. They are not commands to react to.