I didn't enjoy Empire very much at all, but I really don't think the core mechanics of the game where that less complex than other tw games.
The only "trying to appeal the broader audience" I've felt is the marketing is more pointed to the american audience rather than the european.

The only things tha comes to mind is the family tree and sieges that got the big axe, but neither of them where that essential in the 18th century, though I would have enjoyed cultivating different noble families waying for control of the empire. *sigh*

I mean, trading and resources are more complex and have some meaning now, which it didn't have in earlier games.

The building mechanics where streamlined, and at least I thought they did a better job this time.

The same with diplomacy, it was just annyoing that you needed to send diplomats through the whole map to ask for something, a big improvement. Of course, one of the reasons I don't enjoy empire, is the incredibly broken AI diplomacy.