Counterfeit cards are often sold in packages containing more than 9 cards or as sets of multiple packs
About which packs to buy, actually it does not matter that much since the probability of getting what you want is low, but, to maximize it, Id recommend getting Amonkhet for Hazoret the Fervent, Glorybringer, Ahn-Crop Crasher, Magma Spray and Sunscorched Desert
Link Monsters can count for as many materials as their own Link Rating, which is also used in place of Level or Rank
The Secret Rare foil is somewhat of a detriment to the art, as the foil makes it difficult to see the Kashtira Arise-Heart and the buildings through the black and red
What Are Foils and Enchanted Cards
Once your speed is 4, you've achieved "max speed," and your speed can't go any higher