The only thing with IV and V that come to mind is the Interceptor Frigates. In which case those are their NAMES. Interceptor IV fires missiles as was in the vanilla FOC as a Zann Consortium ship and the Interceptor V is in EAW and fires torpedos (though it was called Interceptor III we named it V since it's better than the ZC one)

Observer mode AI should be managing their building and station upgrades fine enough for the ones they actually use such as income and production ones, along with the main starbase. Idk how hands are you are being in the mode, also the AI doesnt get the income buffs that it normally would since it's not AI it's a player technically.

Hero upgrades is something the AI doesnt do. It cant know to build a relay station and a level 3 shipyard and then bring X hero to Y planet and then build the upgrade. Normally heroes for the AI start out upgraded but Observer Mode is basically setup like a normal player just meant to watch how the AI handles the start of the game.