My biggest frustration with the Mine Launcher is the inability to vary how far mines are launched and deployed. I'd like to see a function incorporated that allows you to do so. I see it working like this:
The longer you hold down the mouse button, the further it launches. A quick click will drop the mine and deploy its balloon almost immediately (0.5s), while holding down the mouse button to maximum will launch it the full distance before deploying the balloon (3.5s). It would take 3 seconds for the launcher to charge to maximum launching distance -- 1 second for every second added to the balloon deployment delay.
Depending on balance issues, the actual arming of the mine's warhead may need some changes if this function was added. Personally, I'd like mines to always arm 0.5 to 1 seconds after the balloon deploys, no matter how far the mine is launched. Thus, a "dropped" mine would arm in 1 to 1.5 seconds, while a fully launched mine would arm in 4 to 4.5 seconds.
Another factor that would most likely have to be adjusted would be the reloading time of the launcher. Currently it is 4 seconds, but with this function added, where it takes additional time to launch the full distance, it might be reasonable to take the time down to 3 or even 2 seconds.
This function would make minelaying less dependent on the position of the ship, allowing gunners to drop mines precisely where they want to. It would also open up some interesting gameplay options, where an airship could drop mines immediately behind them to shake off a pursuing enemy or quickly lay a few mines as they cross the path of a less maneuverable airship.