Ruby Storm wants to chain cheap red spells into a big Seize the Storm or Big Score turn, and its cost reducers, Goblin Anarchomancer and Thornscape Familiar, are what make those turns work. Red Elemental Blast has no place in this matchup. It only counters a blue spell or destroys a blue permanent, and nothing in their main deck is blue. Seize the Storm is a red sorcery and its Elemental token is red, so neither is a legal target. Cast into the Fire and Thraben Charm are better. Cast into the Fire's 1 damage kills Thornscape Familiar outright and can also hit a second creature. Thraben Charm's damage mode deals twice the number of creatures you control, enough to kill either cost reducer. Thrilling Discovery is too slow against a combo deck trying to assemble a critical mass of mana and cards in one turn, so it comes out. Use the removal early on their cost reducers before they untap and start chaining spells, rather than holding it for later.