Yes, many Android apps run well. Web apps are often better than Android apps (Google Photos, Outlook...) because they are better optimised for the screen format and can display more or offer more functionality. I have not yet tried Linux apps.
- Processor/RAM are sufficient for trouble-free video conferencing, but simultaneous computationally intensive multitasking is only possible to a limited extent.
- Yes, a USB distributor, external screen or keyboard can be connected to the USB-C port. However, there is only 1 USB-C in the device.