Hi maestro! First of all, you are one hell of a player and extremely passionate, lot's of repsect for that!
One of the main challenges with product development is to find the customer fit. What problems to solve for the customer, needs, pains, gains, ... and opposite of that what you are going to deliver as a product or service. I don't think that language would/should be much of an issue here, although italian natives would prefer italian, french natives french, english/american ...... It could also be that southern european people talk a lot more and extensively, and I know in my culture (the Netherlands) we tend to keep things direct and to the point. So we tend to loose interest if there is too much talking.
Question is, also going through the list of wishes above, are people just looking for "I tell you what tone I want, you give it to me, I'll pay for it!" or are people looking at developing the skills to get better everyday in creating/building your own tones. I think these two groups are mixed up now.
I would gladly opt for both options, and if you want my attention to the second one then you need to grab my attention more with shorter video. Shorter storyline: intro about the musician, sound and what gear used as reference --> build the sound in short chapters of amp/cab/effects/lead/rythmn --> outro and tell what's up next time, link to preset
Leave interaction till the end for Q&A, so people need to sit out till the end if they want to learn more.
Maybe even throw in one of your favorite solo licks and teach us (as you are a great Lukather fan ;-) )