

Q1: If I use this card's On Deletion effect to play a Tamer card, can I then use the Save from the part of the effect after "then" to place this card under that Tamer?
Yes, you can.
Q2: Can I process the part of the effect after "then" in this card's When Digivolving effect even if the "if" condition in the 1st process isn't met?
Yes, you can process it. Even if you have more than 1 Tamer, this card's On Deletion effect still gives you Save.
Lv.4 Greymon BT19-020 U Champion | Virus | Dinosaur/Blue Flare <Rush> [On Deletion] If you have 1 or fewer Tamers, you may play 1 [Kiriha Aonuma] from your hand without paying the cost. Then, <Save>. --- <Reboot> (This Digimon also unsuspends in your opponent's unsuspend phase.)
Lv.4 Greymon BT19-020 U Champion | Virus | Dinosaur/Blue Flare <Rush> [On Deletion] If you have 1 or fewer Tamers, you may play 1 [Kiriha Aonuma] from your hand without paying the cost. Then, <Save>. --- <Reboot> (This Digimon also unsuspends in your opponent's unsuspend phase.)
Lv.4 Greymon BT19-020 U champion | Virus | Dinosaur/Blue Flare <Rush> [On Deletion] If you have 1 or fewer Tamers, you may play 1 [Kiriha Aonuma] from your hand without paying the cost. Then, <Save>. --- <Reboot>
Lv.4 グレイモン BT19-020 U 成熟期 | ウィルス種 | 恐竜型/ブルーフレア ≪速攻≫ 【消滅時】自分のテイマーが1体以下なら、自分の手札から、「蒼沼キリハ」1枚をコストを支払わずに登場できる。その後、≪セーブ≫。 --- ≪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)