Wouldn't take a tier 1 or 2 player to communicate fundamentals, just takes intelligence in the sense of knowing how to organize the ideas and some basic knowledge of video editing to assist presenting them. I could do the former but no idea on the latter.
Video 1 would be showing how to build halls. "You want to build your hall as close to the gold mine as possible while maximizing the flow of gold - you don't want your peons to get stuck or be bumping into each other." *Cut to examples of bad halls, explaining what is happening. One where it's too far away, one where the flow is impeded (bad placement in 11, for example), one where you put buildings in the gold flow.* Then show the standard hall placement for each spot while simultaneously touching on the spot numbers.
Video 2 would maybe be a good time to go over popout order and the concept of wall ins. Show a barracks walling in 11 by itself, show it getting attacked and point out how the peons are able to repair it safely. After that show how grunts pop out of it, followed by some more advanced popout order stuff (build a smith behind the barracks, pointing out how it affects the popout to outside the base), finally followed by a tower below 9's mine which combines both principles simultaneously - the peon pops out to the left and is now safe to repair.
Video 3 would show how to do a basic rush. Start out by touching on the fact that the key to a rush is having gold, and you should never stop making peons throughout the game, *cut to a brief 20 second clip of making a peon, doing stuff while it builds, immediately making another one, etc, pointing out what you're doing ("See, as soon as it's done I immediately make another, this needs to become a habit for you"*. Then show a basic build order of farm rax farm smith, then tell them the same principle of never stop making a peon applies to not stopping making grunts. Tell them to upgrade first level shields as soon as they can, first level swords as soon as they can.
Video 4 would continue with the basics of grunts/rushing, focusing on two things. The first would be the principles behind retreating. "During the early game, every grunt is important and can be the difference between winning and losing." Show a clip of a player losing 2 grunts to 4, then show a clip of that same situation but with the two grunts retreating, joining back up with five grunts, killing the four grunts, then running into the 4-grunt base and winning. The second thing would be chokes. Would be best to show a 3v1 choke to make the advantage more visually apparent, followed by the standard 4v3 choke at 2. Could potentially follow this up by going into flanking, where a group of your grunts attacks a straight line of grunts on the end, which essentially combines the principles of microing grunt movement and number advantages.
Video 5 could start out being all about tower battles followed by avoiding standard lethal weaknesses to towers at the applicable bases (behind 4, 5, 6). Basically a guide to not dying in the first two minutes of the game. I think this would be a good time to go into it, as two of the three most important fundamentals have already been covered (peon creation, popout order). The other fundamental, which would be taught now, would just be how towers work - how far they shoot, counting the spots to create repairable towers, etc.
Well I'm getting lazier with each post so I'll stop for now but I think that would be a fine way to organize the first five videos if anyone had the motivation.