As with most products, the improvement plateaus, and the gains are much smaller once you reach a certain point. If you go super cheap, you are likely not getting a great product ($10 or less). If you move up to a $25-$75 tri-ply pan, you can see a meaningful difference in ease of cooking. If you spend $200+ for a pan, it may be better than your $50 pan, but any improvement is likely less meaningful than moving from a $10 -> $50 (huge difference)... $50 -> $200 (some difference).
False. That's just one of those rumor's that spread from a student's paper to spread round the world. AH! Got this one right. Love my stainless steel and cast iron (and one good non-stick egg pan). I keep my stainless spotless and looking new top & bottom with Barkeepers Friend powder and a 3M pad. Doesn't scratch and it really really works. I'll have to give the salt on iron trick a try. A bit nervous any remaining salt might promote rust. I do oil after cleaning though.
Filming at 720p makes a HUGE difference. Also, keeping your videos less than 30mins is a very good idea. I think the sweet spot is prob ~15-20mins. It may be worth it to break down longer videos into two parts. It's just more easily digestible.