Their graveyard is their discard pile, where most cards are sent after their effects are used up or they are destroyed by an opponent
It also helps Limited play since you're not screwed if you start drafting infect and it gets cut
Creatures can use the regenerate keyword to avoid dying from deathtouch, and preventing all damage (such as with the instant Fog) also prevents deathtouch from activating
The highlight had to be the game in which I cast Sneak Attack off Gonti, Lord of Luxury, then fetched up the Blood Crypt I needed to activate it, winning me the game
The first is the obvious coin-flip deck, where you'll have a little more control over its effect
Yes, Vampire Commander decks can be competitive, especially those led by Edgar Markov or Anje Falkenrath