3. Outpost/resource destroyed notification. This notification should send you to the location where it happened. Outpost in the north-west is often not enough of an indicator for you to find it yourself. In addition, it should have on icon on the right side like most of the other notifications.
I'd put this higher. Or in fact, maybe the entire notification needs a rethink. It's been so long since I've played an old-school strategy game that I'm not sure how they handled AI turns. Think this calls for a post in of itself. The AI going from fog to fog without you being able to see it comes to mind.
2. Resource-building notification. Currently, you get notified each time a new resource is in your territory, even if you aren't able to use them yet. It would be better, if those notifications would only show for up for those resources you could actually use. It can be quite frustrating later in the game, when you have researched the necessary technology to use a certain resource, but have now to hunt all over your territory to find each instance of it yourself.
Not true, least not entirely. Many people will change their tech trees (and even intentionally holding back on the relevant tech) based on a new resource that their leveled/upgraded city can now grab. Possibly a less invasive notification, but not entirely removed.