Q1: Does this card's Opponent's Turn effect prevent it from being deleted even if this card's DP becomes 0 due to an opponent's effect during my opponent's turn?
No, it's deleted. Deletion when DP becomes 0 is due to the rule processing, not an effect.
Lv.4 Tortomon EX7-041 C Champion | Vaccine | Reptile/NSp [Digivolve] Lv.3 w/[NSp] trait: Cost 2 <Blocker> [Opponent's Turn] Your opponent's effects can't delete this Digimon. --- Inherited: <Reboot> (This Digimon also unsuspends in your opponent's unsuspend phase.)
Lv.4 Tortomon EX7-041 C Champion | Vaccine | Reptile/NSp [Digivolve] Lv.3 w/[NSp] trait: Cost 2 <Blocker> [Opponent's Turn] Your opponent's effects can't delete this Digimon. --- Inherited: <Reboot> (This Digimon also unsuspends in your opponent's unsuspend phase.)
Lv.4 Tortomon EX7-041 C Champion | Vaccine | Reptile/NSp [Digivolve] Lv.3 w/[NSp] trait: Cost 2 <Blocker> [Opponent's Turn] Your opponent's effects can't delete this Digimon. --- Inherited: <Reboot>.
Lv.4 トータモン EX7-041 C 成熟期 | ワクチン種 | 爬虫類型/NSp 特徴に「NSp」を持つLv.3:コスト2 ≪ブロッカー≫ 【相手のターン】このデジモンは相手の効果で消滅しない。 --- Inherited: ≪再起動≫(このデジモンは相手のアクティブフェイズでもアクティブになる)