I remember Derek posting that the design intent was to require the players to civilize the land thereby protecting the caravans. What was aggravating was having monsters running around, in your ZOC, without some kind of warning that they were there. The "exclamation point alert for monsters within your ZOC" resolved that issue.

As someone who's played my fair share of games since Sep '10 I find the alert resolved my caravan safety maintenance concerns. If I'm going to build a caravan route outside my ZOC, I'd better be prepared to clear the area and keep it clean. The best way to resolve it is to civilize a safe route for caravans which is why I like playing a bard/charisma build sovereign - he helps to get settlements to level 3 quickly so ZOC's push back monster spawns. The goal is to shrink your vulnerable kingdom/empire border to as small a length as possible.

I never send caravans to enemy cities (unless I want a quick way in to rampage). I let the AI do it. I'd rather build a solid road network in my kingdom (for quick movement and logistics) and always send one caravan to my capital (stackable gold bonus).

yes i want this to happen as well.  we need a way to protect them.

Honestly I don't find that physical caravans add a lot to the game. I would prefer that trade routes and the corresponding roads are automatically established between cities, growing as your empire grows (this would also likely fix the dump all caravans on one city exploit), and bandits (not animals) could blockade them.