[AccessD] Primary Key Best Practices

  I don't agree with that 100%.  Surrogate keys are in widespread use and
for most tables are used 98% of the time in today's designs, but I think
it's really silly to add a surrogate key to a many to many linking table
when you already have a FK pair that must be unique and would serve
perfectly well as a PK.

======Other than habit -- consistency can be a good thing. 

Now to add to your list -- and you can thank Martin Reid for this additional
few: 

PK should be stable. In real life, things do change, hence cascading
updates, but use a key that's not prone to change.  
When using natural keys, choose the key with the fewest fields necessary --
I know that should be a given, but I've seen some that made me shake my
head... :( 

Susan H.