I am new to this and have several questions; ultimately I am concerned with the ways in which a person can be physically tracked though internet activity.

I know an IP address can be traced to a geographical area but are there ways to  trace it back to hardware, i.e. a specific computer and therefore its owner?

Can an IP address be traced to a router address and from there a MAC address? When you send e-mails what addresses are sent?

If you are using a VPN or a program like Tor which change and hide IP addresses, can hardware be traced?

very new at this looking to get some help! thanks