

Q1: Can I activate this card's Main effect even when my opponent doesn't have any Digimon that can be deleted?
Yes, you can.
Q2: My opponent has a Digimon with 4000 DP or less. Can I meet the "if this effect didn't delete" condition in this card's Main effect by not choosing a card to delete?
No, you can't. If your opponent has a Digimon with 4000 DP or less, you must choose that card and delete it.
Q3: My opponent has a Digimon with 4000 DP or less. Can I meet the "if this effect didn't delete" condition in this card's Main effect by choosing an opponent's Digimon with an effect that prevents deletion and 4000 DP or less?
Yes, you can.
Lv.4 Meramon BT25-014 C Champion | Data | Flame/Iliad/TS [Main] [Once Per Turn] By trashing 1 [Flame] or [TS] trait card from your hand, delete 1 of your opponent's Digimon with 4000 DP or less. If this effect didn't delete, <Draw 2>. --- [When Attacking] Delete 1 of your opponent's Digimon with 4000 DP or less.
Lv.4 Meramon BT25-014 C Champion | Data | Flame/Iliad/TS [Digivolve] Lv.3 w/[Flame]/[TS] trait: Cost 2 [Main] [Once Per Turn] By trashing 1 [Flame] or [TS] trait card from your hand, delete 1 of your opponent's Digimon with 4000 DP or less. If this effect didn't delete, <Draw 2>. --- [When Attacking] Delete 1 of your opponent's Digimon with 4000 DP or less.
Lv.4 Meramon BT25-014 C champion | Data | Flame/Iliad/TS [Digivolve] Lv.3 w/[Flame]/[TS] trait: Cost 2 [Main] [Once Per Turn] By trashing 1 [Flame] or [TS] trait card from your hand, delete 1 of your opponent's Digimon with 4000 DP or less. If this effect didn't delete, <Draw 2>. --- [When Attacking] Delete 1 of your opponent's Digimon with 4000 DP or less.
Lv.4 メラモン BT25-014 C 成熟期 | データ種 | 火炎型/イリアス/TS 【メイン】[ターン1回]自分の手札から、特徴「火炎型」/「TS」を持つカード1枚を破棄することで、DP4000以下の相手のデジモン1体を消滅させる。この効果で消滅しなかったなら、≪2ドロー≫。 --- 【アタック時】DP4000以下の相手のデジモン1体を消滅させる。