That depends on which key you're referring to. On the Macbook, the left arrow key is right next to the up/down half-keys. If you touch to the right and you're hitting another full key, you're not at the arrow key.

Again, I don't understand how the bump on the F key works but somehow the giant dip in between the two up/down keys is the problem...?

The issue I have is that I will rest my index finger on the Option key instead of the left arrow key because they feel the same. The dip is fine for the up/down keys, but I can't "rest" my index and ring fingers on the arrow keys anymore.

Why not? Rest your middle finger down where you feel the break. Your index and ring fingers are now on the left and right arrow keys.

This is such a non-issue.