So, before i even dream about that. What are your personal top 3/5/7/10/1000/ROFL things the majority of "Bad" lets players and good lets players do to keep you watching and/or throwing your monitor out of a window in frustration

LP's are tricky for a game like Skyrim. If they're side scrollers or old retro games, that's the low hanging fruit.
How do you intend to handle those long trecks to your quest locations? You better have a pretty damn good commentary constantly coming out.
Are you going to open decisions made to your audience? A lot of LP's do this when there's choice involved. Not at EVERY choice, but the pivotal ones. IE, who to side with during the Civil War, whether to side with Delphine or Parth, etc etc...

Also you need to have a "good" voice. This probably sounds rude, but if I don't like the sound of someone's voice I'm not going to sit and listen to them talk for half an hour.

Yeah, you need to have a good voice, and a strong delivery. And a good mic. The only thing worse than bad mic quality is bad video quality.