Nice article, just followed your steps on our databases. :-D
Though for general purpose, I'm missing some short explanations on ANSI settings and as you check them in step 2) and it's not only about ANSI NULL.
In step 4) I first was kind of surprised as the sql-statement will find other "= NULL"s, too (e.g. SET @Var = NULL). But it shows a starting point for checking your code automatically and fast.