It is a 'gamey' aspect of the game I'll admit. All sides play on the same field though. Another thing to consider:
When the CV is positioned at the port, it is removed as an offensive weapon, as it is reduced to a defensive role only.
Also, when the CV is killed, it re-spawns to some preset location. I think that reset location rarely coincides, if ever, with the dry spawn location. In other words, the CV then has to be moved to the new location. (albiet relatively close.)
So, although it takes herculean efforts to capture a port like this, it is not impossible. You have to kill the cv, reduce the port, and have a bomber on station to kill it again when it spawns.
All that being said, I like your suggestions. I think the 'dry spawn' ability should just be removed.