It will be nice if it will be as informative as Leaguecraft Lectures by Unswlolsoc.
Full games are good too. You can cut/fast forward uninteresting parts if you want (that's what i did with my videos in one other game).
How much should I explain, every single detail, when and why I trade, how I do my last hitting, when I think about roaming, etc.
Yeah, why not? People who will watch it aren't likely to be Diamond. So, even if they already know it, they're not a masters of it. It's not bad to be reminded how to do it properly. And it will help people who don't know it even more.