This lets you play what is essentially a reanimator deck for instants and sorceries, focusing on those with flashback and jumpstart, and accruing value over time through repeated looting and recasting
Well, in true "every ability is kicker" fashion, we now have the tiered ability
This means that you can absolutely put lands and artifacts that generate colorless mana in decks of any color
Some cards have hexproof from specific colors or card types
I have no idea how your opponent survives double pump hasted Cavalier plus anything else, and the Loot effect makes it easy to assure you have that something else after the fact
A station symbol means "As long as this permanent has N or more charge counters on it, it has [abilities]," where N is the number inside the symbol and [abilities] are all the abilities found inside the same striation as that symbol