The key part that I paticularly like is the taunting, which is somewhat basic, but still, It taunts to everyone! It has civilization specific unit creations, which is a good thing. And it changes through the ages. I tried to make it so that it waits between attacks, but it is just like me: It just doesn't wait, nor does it give mercy. It even taunts you when you first attack it, and even when a normal computer resigns, it instead taunts you again, telling you that you've got to defeat him, cause he ain't resigning. Too bad the ai can't respont to your taunts, because then that would be where the fun really would start!
Imperialist is an AI meant for play in the castle and imperial ages, it has no defenses against a flush and will only start to produce in the imperial age. It never has the resources to build much, so only a relatively unskilled player would be able to derive much of a challenge from it.
Your AI doesn't manage a good economy. At the beginning, it won't build its first house until it reaches 5 pop, including scout. This means that its town center is idle for about 45 seconds. I noticed it harvests gold and stone very early on, which is generally not a good idea when all avaliable vills should be collecting food. It doesn't even build a mining camp, but instead has villagers walking large distances to and from deposits. Add to this factor the issue that it only assigns a couple of vills to collect food in the dark age, and that it has a lot of idle town center time, and it will be unlikely to outlast the feudal age if you flush. Another problem is the unbalanced economy. Usually it will end up with only a couple hundred food, but over a thousand gold and stone.
It goes to castle with 15 villies, and only builds a few more before trying to advance to imperial. With such a weak economy it is very slow. It builds a castle in transition to imperial, and immediately upon hitting the final age it makes trebuchets and some skirmishers which it never upgrades. Usually you'll see it trying to forward-build by constructing a castle on enemy territory, and then attacking with trebuchets and crossbowmen.
One good part of your AI is that it grabs relics quickly. Once gold runs out (considering how many villagers are assigned to mining, this happens much sooner than in other AIs), relics provide it with a welcome income of gold. Relics are a part of the game many AIs seem to neglect. The trouble is, it is so slow a human player will normally have taken the relics by the time Imperialist reaches castle. :S
While good for a first effort, Imperialist is lacking in so many aspects I can't recommend it to anyone other then newbies.