A pair of doubts

[Volcano Man]

In regards to the first, the only thing you can do for the AI is just give them orders -- you can't really do anything beyond this.

In regards to the second, well, that depends. You can surely have situations where naval units can fire on each other, but since they act like artillery units then they would essentially be artillery units firing at each other either indirectly (beyond visibility range) or directly (within LOS). So, it might not be "realistic" is so much of what naval requirements would need, but I think it will work as long as the attack and defense ratings are reasonable.