If you're trying to keep it short:
I'd leave out the full minute of talking about looking for wear on the bottom of the BCG. A gun that's been test fired and messed around with by the tire kickers is going to show some wear on the BCG. If you're going to take out the BCG you should look for proper staking.
I'd leave out the over a minute carry handle tutorial. Also if you have an electronic sight you need a BUIS, not a carry handle handy.
Use that time to touch on chrome lining v stainless/other, twist rate and ammo selection, proper staking, etc.
The carry handle IS the preferred backup sight. In the army we had a choice of those or the KAC flip sights. All the SDM's carried the handles tied off to their gear. The flip sights aren't all that accurate, and I'd definitely get a fixed front sight tower. Sometimes it ghosts in the optics, but not enough to get in the way really. Anyone using an AR should really invest the time to learn to use that carry handle properly anyway. If you can shoot with it proficiently to 600m and know how to make and record adjustments and actually USE the thing, I guarantee you that you will become a better shooter overall.
The video wasn't all that bad, I did notice when you showed the 5.56 marking it had the twist as 1/9. This is not the best twist for 62gr. bullets and above, 1/7 is. 1/9 is the twist varmint shooters use for their 55gr. pills. I'd mention that, since a lot of new folks won't even know what that means.
Mentioning the difference between milspec and commercial parts is good too.
When looking at the BCG for wear, another thing to look at, for whole complete rifles anyway and not a personal build made from parts, is to look for machining marks on the bolt carrier itself. Junk builders and makers that cut corners leave a lot of milling marks. This is a sign of poor attention to detail and a sign they don't care much about their product. For instance, for a good comparison, compare a JP Enterprises Tactical Bolt Carrier to an Olympic Arms bolt carrier. Then compare the prices and tell me if it is worth the savings to go with the Oly.
Also look at the trigger group when the weapon is broken open. If the engagement surfaces of the trigger and hammer are parkerized or treated, this is a sign of poor attention to detail, cutting corners, saving money. Those triggers cannot be polished and will always feel stiff and gritty. Again, Oly does this. DPMS does not.
Also important is to take a flashlight to the bore. Also be aware some cheaper builders "forget" to properly ream the chamber and so if you are intent on buying a cheap rifle, making sure it actually will work is advisable. Here dummy rounds can be helpful, I guess snap caps would work too.
I've seen it all. Based on that, I build all my own AR's. I can just do a better job on my own. But if I had to recommend one rifle that is both well built and real good gear for the price, my vote goes to LMT. Their M4 rifle is very close to a real military M4, I have one and I love it. Noveske is the best, but more costly.
