In the version I am playing right now the AI uses armor just fine (though it lload heavy armor until there is less than 7 left, then light until there is less than 3 tons left, and then loads light, because that is what I told it to do). The AI cannot use structural suports because they have no weight and you have to give the AI design parameters by weight (or tell it to use just one, which would be silly).
The current armor system is not complicated at all, for the player. He knows that research invested in armor will yield incrementally better armor. There is always a new version of armor awaiting amy given investment.
My only issue with the armor system (besides the structural supports, which I think was a neat idea but will not use because the AI cannot use it and it is unclear how the player should use it) is that it is unclear to the new user that you need to research chunks of armor advances at once, or else not at all. Otherwise, all you are doing is creating a huge chunk of components that will be replaced on your ships, but from which you gain little benefit (and battleships with 20% armor have a LOT of armor components).
One way around this is to size armor for the hulls, making each armor worth, say, 5% of the hull size, and scaling using mounts (as is already done for engines). Another way is to create some larger armor components. However, I don't now how either solution would affect the "leakiness" of the existing armor, so I am leaving those considerations for the end of my analysis and hope someone else solves them in the meantime!
IF - thanks for the tip on the tech gridder. It will help a lot.