I definitely think the number of visitors to the avenue increases but not nearly at the rate at which Present assumes; at rank 10 I usually got 4 NPC characters, and currently on the Japanese game at rank 34 I'm getting around 6 or 7 people per day. I keep a printed list of all the possible sentences available, so from that regard I rarely get caught out with incorrect directing of people in the avenue. It's getting to the point where certain phrases come up and I know instinctively where they are in the list to check. I've not had any problems with Male/Female clerk directions though.
I don't tend to take a huge amount of notice into what Serebii's list says on the points given for correct directions, because I've had a number of instances where it gives flat out more or less points than it should (even factoring in fans giving only 75%). It's kind of the same thing with the Markets and Antique Stores not selling their full complement of items until post-game. Antique Stores don't sell the 'Rock' series of items for example, but this is explainable as most of the items in this set are fossils which only become practical post-game.
Also, with clock issues, when I changed it for DST, I didn't begin to play the game until Tuesday after resetting on the Sunday morning. Now, under normal circumstances, this covered 24 hours plus an additional midnight before I began to play again, but when I logged back in, the avenue shops were still empty. It only began restocking items the following day.
Fire type enthusiast since 1998