Justin Alexander joins in the discussion of how rows are numbered in theaters…
I have never encountered all three of those features in the same venue, but I have encountered them separately while working as an usher. Or, more commonly, what happens when the venue doesn't do it.
Z -> NN: People see "AA" on their ticket and they think "A = 1 = I'm sitting in the front row." Then, when they get to the theater and discover that this is not the case, they argue about it. You'd think the NN thing would cause the same problem if they thought they were sitting in row 14 only to discover they're in row 27, but apparently people don't get that emotionally invested in the idea of being "14 rows back."
I haven't actually seen a venue that skipped I or O, but I have had patrons tell me they can't find row I. Instead they'll say, "Here's H1, here's J1, and between them is seat 11." So while I think it would be exciting to sit in seat OO7, I suspect this is why they eliminated those rows.
With that being said, it probably backfires more often than not. When I worked in a venue which skipped a row letter in one section for completely unrelated reasons (because of how the seats were laid out), it would frequently result in people sitting in the wrong row because they predicted their row from a distance ("this is H, so four rows up should be L") and would end up one row off.
I often find it hard to find my row in a theater because the rows are so poorly labelled — microscopic placards that have sometimes been there for 50+ years and have faded over time. So if I'm heading for (let's say) Row "G" and I can read the label on row "M," I start counting from there. It occasionally gets me into the wrong row but only because the label on my row is illegible or the person in the aisle seat has his coat over it or something.