Can Mystical Space Typhoon Destroy face down cards?
Mystical Space Typhoon is a Quick-Play Spell card. You can activate it during your opponent's turn if you set it face-down in your turn. It's so satisfying when they use an effect to destroy your face-down MST, only for you to chain it and destroy one of their Spell or Trap cards.
Does trap hole negate summon effects?
"Bottomless Trap Hole" does not negate a Summon. It destroys and removes from play [sic] the monsters after it has already been successfully Summoned.
Do card effects include spells and traps?
Card effects include monster, Spell and Trap effects. The card effect, as well as any costs and conditions (and Materials for most Extra Deck monsters), are detailed in the card text.
Can MST destroy itself?
In general, if you cannot apply the card's effect when activating a card, then you cannot activate it. Thus, if there are no cards on the field that can be destroyed, then you cannot activate "Mystical Space Typhoon" nor a Set "Raigeki Break". Also, when you activate "Mystical Space Typhoon", it cannot target itself.