1. Depends on your requests and templates, but a room composite request recording 1080p 30fps with a relatively simple template should use something around 4 CPU and 1G memory
2. Each egress has its own audio device, virtual display, chrome window, and gstreamer pipeline
3. Yes
4. See the docs for more info:
https://docs.livekit.io/server/egress/#service-architecture
5. That is certainly possible