Thank you. Yes, I completely agree. Having a convention is the most important part; I only gave my recommendations.
Indeed I did not tackle the self join issue. Thank you for your example! (I hope I fixed your code correctly?)

I think your recommendations are fine. You are, however, missing any recommendations for how to name aliases when you use self-joins.

I find that sometimes, the alias may even be longer than the table name:

SELECT later_customer.*
FROM
  customers AS first_customer
  JOIN customers AS later_customer ON (first_customer.cust_id = hypothetical_earlier_customer.cust_id)
WHERE
  hypothetical_earlier_customer.cust_id IS NULL;

By all means, this is not a discussion on triggers. There’s an algorithm beside the triggers here.

If you truncate, the table will be locked until the space has been freed (8-10 seconds for _very_ large tables, if you have IO at the same time). If you do the renaming first, the empty table will appear _very_ fast, while the dropping of the old table does not involve locking of any table that is in use, and so – probably doesn’t matter much if it takes a few seconds.