Well, I agree that the planetary combat need some modification...
As of now, we can already do some things :
* Drop Wp altogether, I don't like them, that's not SciFi as I want it
* Make population much more resistant to damage : it just hurts me to see a lone "Escort" killing 100M people with its DUC1...
even if it supposed to weigh 150KT that don't help, what I see is a small 100 m long craft...
* HEAVILY Shield planets/facilities !! That's what B5 mod did, along with shield skipping bombs ! That's very neat, to kill planetary stuff you have to use bombs instead of rays
With this planetary attacks should look better IMHO. If I ever do a mod I will begin with this ...