Life gain is largely incidental in these cases, used as a buffer for the Draw-Go strategy
Try to pack some tools in your colors that will extend the game or dig you deeper into your deck, like cheap removal spells, counterspells, card drawing, and board sweepers like Wrath of God and Damnation
Thats thanks to the Rush keyword on the Rafiki, Mysterious Sage card, which allows the three-ink card to challenge immediately on the same turn its played
Matoya, Archon Elder has some very welcome reminder text that you draw after you scry, and that it is best way
You don't care what happens to the permanent, but you'll get all the coin flips you could possibly need
(As long as the library was completely random to begin with.) The way to see this is by looking at the definition of randomness: "The position of any one card carries no information about the position of any other card." The fact that the top card was the card they were looking for therefore can't tell them anything about the rest of the library