It's hard to offer really concrete advice without a bit more information on the specific context in question, but here are some general pointers:
- You probably shouldn't duplicate the content across YouTube channels. You can't Geotarget YouTube channels and in practice, this is not really any different from having duplicate content across multiple websites. If you do duplicate the content, you'll cannibalise the effectiveness of the videos ranking on both YouTube and Google organic searches, plus you'll split the view count which will harm your YouTube optimisation.
- Absolutely 100% do not put the sales focused product videos on YouTube - as in doing so you'll drive traffic to YouTube instead of your own site, which means you're adding an unnecessary step in the conversion funnel which will probably cost you money. You cannot sell from a YouTube channel and external links on YouTube get extremely low click through rates, with very very few people going to YouTube to search for products to buy (you only go to YouTube to watch a video). There is a bit more information about this for you in these links: http://moz.com/blog/the-marketing-value-of-youtube , http://moz.com/blog/building-a-video-seo-strategy, http://moz.com/videos/view/2013/building-a-winning-video-marketing-strategy
- Annotated external links do not get clicked very often, I wouldn't rely on this as a strategy at all. It basically won't work.
- You can't geotarget annotations, no.
So, in short - I probably recommend just having a single channel and only putting the entertaining videos on YouTube. bear in mind that YouTube doesn't drive much traffic, so your goal here should be brand awareness, not traffic acquisition.
I hope that's useful!
Thanks,
Phil