A:Answer I've had mine for 3 weeks, and it is a terrific Chromebook. Yes, you can use external disc drives, SSD drives, SD Cards etc. by connecting them to the USB-C ports or using a USB hub that's connected to the Chromebook.
I've enabled Crostini Linux, and installed several apps including Firefox-ESR, the full LibreOffice suite. GIMP photo editor, and some Linux utilities (file manager etc.) So far it works great given that this Chromebook has 16Gb RAM. (finally!) I also really like the low power consumption and thus fan-less design for quiet and low heat.