Not necessarily the NIC itself. But moving the hard drive from a dead
box to a new box will have the same effect. This is done more often,
I guess.
Maybe, but still not often enough to worry about.
There are many such issues. Dell designed biosdevname to solve actual issues that customers ran into with Dell systems that they pre-bundle Linux with. You may not run into such issues with your laptop but people who manage multiple boxes certain were dealing some of the hassles