I'm not familiar with the video but there are times when a heat gun is good to use to cause swirls in the wax, blend two colors etc., but those are special techniques for various kinds of candles. I think one was to provide a motion/blur look. I will use it to bleed colors or release air bubbles if I suspect a certain press technique squished out the bubbles. Easier to show than explain I suppose.
I wouldn't use a kitchenmaid for jack with wax. Too much money goes into that apparatus, doesn't it? A regular hand mixer would suffice just fine if I wanted to whip wax. Otherwise, I have no need to incorporate air. Bubbles are fine etc. for a rustic look, but not everything should be rustic.
Adding FO to heated wax should be good enough, however, in the winter and, in some cases year around, there are fragrances that will be difficult to incorporate. Those might require a little extra heating or some stirring to incorporate.
What I've noticed about heat and FO is that heat helps the scent to blossom, but you don't have to do anything special to make that happen.
I use a fry daddy as my vat for melted wax and the fragrance goes in there when everything else is melted (wax and additives). I pull out by cupfuls and color that portion, pour and repeat as often as needed, but then I don't make many solid colored candles. The fry daddy remains on through the entire series of pours, which frankly is at a low temp. There are times when I'll use the heat gun to knock down any splashes in my mold and times when I'll use it because I forgot to make splashes. I don't use it, though, to swirl my wax and fragrance together.