Well we gave the RSN spook cruisers the ability to launch mines and then immediately took it back, they're plenty powerful as is.
We use Stoobert's radial movement system and a modified damage effect where a ship at half hull moves at half speed, gains +1" turn radius only loses two dice from the total AD pool. Helps make damaged ships usable but vulnerable.
I came up with a repair mechanic in another thread some time ago where you make your repairs from a pool of dice equal to your current crew rating, succeeding on a 5 or 6. For example, I have 5 crew so I'll roll three dice against this corrosive marker and two against the hazard marker