@BigSteve57 You answered a lot of your own question! Yes, in heavy bush you will have shots that are very short distances, well within the capabilities of the 30-30. And yes, shorter, lighter, easier to maneuver! Also a lever is (typically for most people) a little faster to cycle than a bolt. Another factor is recoil. (There's a reason your wife shoots a 243 and not 30-06 right?)
Why subject yourself to unnecessary recoil if you don't have to? And possibly the biggest reason would be what you said about the pencil sized whole in and out and what you said about having to be a little careful about shot placement for fear of losing the deer. Not as much of an issue with the slow moving 30-30. They seem to expand well in a deer, even at close range. (Compared to a 30-06 or similar) Which brings me to the final point, that you're more likely to have a bullet exit the far side of a deer with a lot more speed and energy with a 30-06 (or similar) than you would with a 30-30. In dense bush you can't see very far, and I'm sure you'd agree that you don't want a "stray" bullet going through the bush where you can't see what, or who may be in it's path. Don't get me wrong, I'm a huge fan of the 30-06! It's a favorite of many hunters everywhere, and for good reason! As I said, versatility probably being the best reason. But in thick bush, and thick bush only, I don't see an advantage to the 30-06 over the 30-30.
But I also know for myself that I seldomly find myself ONLY in thick bush, and that is a whole different conversation!