The first is pretty simple: its a cool surprise to find cards like Ancient Tomb in a regular, Standard-legal booster pack
I count a whopping 43 cards that are either Zombies or support Zombie Tribal, and 19 cards that deal with sacrifice, with a lot of overlap between the two themes, as many of the Zombie cards either sacrifice themselves (Ravenous Rotbelly)or have beneficial triggers when you sacrifice Zombies (Undead Augur)
Its not the most pro-social card, but its also one that I think is mostly reasonable as a way for these decks to try and take a win against control decks that seem to have hands full of answers
How you construct your mana base is an intrinsically linked set of decisions, and you should ideally do both at the same time
If you ever have to calculate Just Desserts, you have my permission to use 3.14
Herald of Anguish's end step triggered ability works surprisingly well in combination with your opponent's The Scarab God end step triggered ability after it dies