These TCG rulings were issued by Upper Deck Entertainment and have since been deemed unofficial by Konami. They were previously considered official and can still be correct, as long as they follow the official gameplay rules, or unless Konami has issued a ruling that says otherwise. References: 
This card can remove from play multiple monsters at once, if they are Summoned simultaneously. Since this card can affect multiple monsters, it does not target.
If the opponent has "Lord of D." on the field and activates "The Flute of Summoning Dragon" to Special Summon 2 copies of "Blue-Eyes White Dragon", you can activate this card and both will be removed from play. "Lord of D." does not protect the Dragons because "Bottomless Trap Hole" does not target. The same situation would occur if only 1 "Blue-Eyes White Dragon" was Special Summoned, "Bottomless Trap Hole" still does not target.
This card can only be activated when the last thing that resolved in the Duel was the opponent Normal/Flip/Special Summoning a monster(s). It cannot be activated at any other time.
If "Cyber Jar" is flipped during a Main Phase, and the opponent Special Summons "Dark Blade", "Luster Dragon", "Magical Scientist" and a face-down monster, you can activate "Bottomless Trap Hole" and both "Luster Dragon" and "Dark Blade" will be removed from play. The "Magical Scientist", face-down monster, and all monsters you Summoned will remain on the field.
If "Cyber Jar" is flipped as a result of being attacked, you cannot activate "Bottomless Trap Hole" because it cannot be activated during the Damage Step.
If the opponent Summons a monster, then you activate "Bottomless Trap Hole", and the opponent chains "Book of Moon" to flip the Summoned monster face-down, it is not removed from play by the effect of "Bottomless Trap Hole".
Use the current ATK at time of Summoning to determine if you can activate "Bottomless Trap Hole". So if the opponent Tribute Summons "Enraged Muka Muka" with 1 card in their hand, you can activate "Bottomless Trap Hole" (since its ATK is 1600).
You cannot activate this card after "Jinzo" is Summoned.
You can activate this card after a monster was Special Summoned by the effect of another card, such as "Monster Reborn".
If the opponent activates "Monster Reborn" and then chains "Call of the Haunted" (so that 2 monsters are Summoned in the same chain), and then you activate "Bottomless Trap Hole" after that chain resolves only the monster Summoned by chain link 1 ("Monster Reborn") is removed from play.
Only the monster(s) that triggered "Bottomless Trap Hole" by being Normal / Flip / Special Summoned can be destroyed & removed from play by "Bottomless Trap Hole's" effect. Example: Player A Normal Summons "Dark Blade", and Player B activates "Bottomless Trap Hole" in response (Chain Link 1), then Player A chains the effect of his face-up "Ultimate Offering" to Tribute "Dark Blade" for "Summoned Skull" (Chain Link 2). "Ultimate Offering's" effect resolves first, and "Dark Blade" is Tributed for "Summoned Skull". Then the effect of "Bottomless Trap Hole" disappears because the monster it would have applied to is no longer on the field.
Arsenal Bug: When "Arsenal Bug" is Summoned and there are no other Insect-Type monsters on your side of the field, your opponent cannot activate "Bottomless Trap Hole" because the ATK of "Arsenal Bug" is 1000 when it is Summoned.
Book of Moon: If you chain "Book of Moon" to "Bottomless Trap Hole", the now face-down monster will not be destroyed by "Bottomless Trap Hole", but any other appropriate monsters Summoned at the same time will still be destroyed.
Command Knight: If "Command Knight" is Normal Summoned, Flip summoned, or Special Summoned, its ATK is at least 1600 so your opponent can activate "Bottomless Trap Hole".
Dimension Fusion: You can activate "Bottomless Trap Hole" after monsters are Summoned with "Dimension Fusion"; "Bottomless Trap Hole" destroys the Summoned monsters on your opponent's side of the field, and your Summoned monsters are not destroyed.
Dramatic Rescue: You can activate "Dramatic Rescue" when an Amazoness on your side of the field is targeted... but not when cards like... "Bottomless Trap Hole"... are used.
Goldd, Wu-Lord of Dark World / Sillva, Warlord of Dark World: If "Goldd, Wu-Lord of Dark World" is discarded by your opponent's card effect, when his effect resolves, he is Special Summoned first, and then the second part of his effect resolves. So the opponent cannot activate "Bottomless Trap Hole" [because] the timing is no longer correct...
Imperial Iron Wall: Cards like "Bottomless Trap Hole"... cannot be activated while "Imperial Iron Wall" is active. If you activate "Bottomless Trap Hole" and "Imperial Iron Wall" is chained, the destroyed monster is sent to the Graveyard instead of being removed from play...
Lava Golem: If you Special Summon "Lava Golem" onto your opponent's side of the field they can activate "Bottomless Trap Hole" since you performed the Summon. You could not activate "Bottomless Trap Hole" even though the "Lava Golem" will be on their side of the field.
Magical Dimension: If your opponent activates "Magical Dimension" and chooses not to destroy a monster on the field, then you can activate..."Bottomless Trap Hole" to destroy the Special Summoned Spellcaster. If your opponent does decide to destroy a monster, then you cannot activate these cards because the last thing to happen was not a monster being Summoned. So you have missed the timing.
Magical Dimension: If you Summon a monster like "Skilled Dark Magician" and the opponent activates "Bottomless Trap Hole", you can chain "Magical Dimension" to Tribute "Skilled Dark Magician" and Special Summon another Spellcaster from your hand. This new monster will NOT be destroyed by "Bottomless Trap Hole".
Maju Garzett: When you Tribute Summon "Maju Garzett", your opponent can use..."Bottomless Trap Hole" if appropriate.
Royal Keeper: When your opponent activates "Bottomless Trap Hole" against "Royal Keeper", the +300 ATK effect of "Royal Keeper" resolves after "Bottomless Trap Hole".
Sacred Phoenix of Nephthys: If "Sacred Phoenix of Nephthys" is destroyed and removed from play, such as with "Bottomless Trap Hole", it is not Special Summoned from out of play during the Standby Phase, because this effect activates in the Graveyard.
The Dragon's Bead: You can only activate the effect of this card to negate a Trap Card that targets a face-up Dragon-Type monster, so it cannot negate..."Bottomless Trap Hole"...
Twin-Headed Behemoth: The opponent cannot activate "Bottomless Trap Hole" when "Twin-Headed Behemoth" is Special Summoned by its own effect, because its ATK is already changed to 1000 at the time of Summoning.
Tyrant Dragon: When you Summon "Tyrant Dragon", the opponent can activate..."Bottomless Trap Hole" and destroy "Tyrant Dragon" because neither of these Trap Cards target. (However, "Trap Hole" does target and its effect will disappear if activated.)
Valkyrion the Magna Warrior: The opponent can activate "Bottomless Trap Hole" and "Beta the Magnet Warrior" and "Gamma the Magnet Warrior" will be destroyed.
Uria, Lord of Searing Flames: When a player Special Summons "Uria, Lord of Searing Flames" and activates its effect to destroy a Set Spell or Trap Card, no Spell or Trap card can be chained, including "Bottomless Trap Hole"...[Out of Date 3]
↑Konami Judge Program Rulings are considered unverified, as their source(s) are not publicly viewable. They are not confirmed as applicable to the TCG until they have been officially published by Konami.
Out of Date
↑"Starlight Road"'s newest errata states that it does not negate the activation of the card or effect it was Chained to, which makes this ruling invalid.
↑The latest errata of "D.D. Survivor" states that it can only activate its effect during the turn it was banished, making this ruling invalid.