1
If you are resetting that device, if you choose to remove everything during the reset, that will basically remove everything from the PC including your account and all data on the device, it will be like a full clean installation of Windows.
2
If you choose to keep your files and apps at the start of the reset, your files and account will not be removed from the PC, but you will need to reinstall all your apps.
3
Resetting a PC, regardless of which setting you choose does not affect your Microsoft account online, you will not loose access to your Microsoft account or settings stored on your account online.