Nuke Cannon SSNR Shells and unit promotion Options

Isn't the SSNR shell to powerful? Especially because it need only one nuke cannon. It's 4 times the damage of the original attack and has a wider area of effect. In any case the unit doesn't get promoted while using it. Which brings me to my next case:

There are a bunch of units that are really hard to promote if not impossible because of the secondary effect they have like the inferno cannon burning or even worse the firestorm. Almost every unit that leaves fire, toxins or radiation suffers from this. The toxin / radiation cloud or the burning ground are different instances / objects that do not communicate with it's creator. Maybe something can be done to send back kills / experience info to it's parent. I've seen this fixed in the Westwood mod so it's possible.
Good thing that the aurora alpha is fixed.

[Sharpnessism]

IIRC SSNR also has reduced range in comparison to the normal shells, making it more appealing to use normal shell especially against quicker vehicles which may escape the SSNR blast.