As you already know, the Hiryuu Shouten Ha works with any heat source- including the hentai pervert's out of control lust, as aptly demonstrated in the manga.

Rising Dragon Ascension Defeat? Surely you can think of a better word than "Defeat" to use?

Oh and you theory concerning Ranma's technique may be flawed. If the launch speed was all that mattered, he could have fired his ki-blasts faster before already. 
But if we think of the ki balls as having "weight" then it might make sense that smaller balls can be fired faster than bigger ones.
I better stop before this turns into a discussion on the physics of ki.