Nice index, Imperial Outpost seems to have potential as it evokes sets from the original Pirates theme...
(Should it not be named "Armada Outpost" to be consistent with Armada Sentry and Armada Flagship?)
However, it lacks design innovation and could use more colour.
The structure should be placed at the rear of the baseplate. The playability takes place at the front of the design, so more water frontage makes sense.
Needs more red. Observe how Armada Sentry balances the white and green with red accessories and a splash of yellow.
We've seen plenty square/block architecture in past LEGO Pirate forts, maybe try some curves
The middle of the outpost should not be walled off, it needs to be open - should have an arched window or some clever architecture to open the space up.
Needs a sail boat with a second pirate (think Lagoon Lockup)
Should have a palm tree - this is a staple of sets at this price point.
Some kind of action feature would make things more interesting. John Cook is breaking out, so base an action feature around that.
Even though there are a generous number of accessories, the design still feels a bit empty, although I suspect this is a result due of lack of colour.
Those suggestions aside, this is still a good effort, but it does feel as though I could undergo more refinement.