Not being able to fire at parts inside ships without first destroying the edges is pretty fundamental to the balance of the game, and I don't want to change that.
I'm open to adding interior weapons as long as they don't hurt the balance of the game or make perimeter weapons useless. I also don't want the only disadvantage of interior weapons to be simply that they cost more -- that may "balance" the game but it doesn't make ship design more interesting. There should be mechanical reasons to want both interior and perimeter weapons besides just cost.
My current thinking is that interior weapons will be limited to extremely powerful, extremely expensive "super" weapons that have very low rate of fire and other drawbacks such as they start fires or damage themselves every time they shoot. Thus, such weapons can't be solely relied upon, and you'll still want to have the more reliable perimeter weapons.
However, nothing is set in stone, and I welcome all ideas!