

Q1: Can I meet the conditions for this card's End of Your Turn effect by placing just 2 cards from my trash face down as this Digimon's bottom digivolution cards?
No, you can't. A "by" condition can't be met if only some of the required actions are performed. The conditions for this When Digivolving effect require you to place the specified number of cards from your trash face down as this Digimon's bottom digivolution cards.
Lv.4 Vegiemon BT22-049 U Champion | Virus | Carnivorous Plant/DM/Ver.2 [End of Your Turn] [Once Per Turn] By placing 3 Digimon cards with the [Ver.2] trait from your trash face down as this Digimon's bottom digivolution cards, it may digivolve into a Digimon card with the [Ver.2] trait in the hand or trash. --- <Piercing> (When this Digimon attacks and deletes your opponent's Digimon in battle, it checks security before the attack ends.)
Lv.4 Vegiemon BT22-049 U Champion | Virus | Carnivorous Plant/DM/Ver.2 [Digivolve] Lv.3 w/[DM] trait: Cost 2 [End of Your Turn] [Once Per Turn] By placing 3 Digimon cards with the [Ver.2] trait from your trash face down as this Digimon's bottom digivolution cards, it may digivolve into a Digimon card with the [Ver.2] trait in the hand or trash. --- <Piercing> (When this Digimon attacks and deletes your opponent's Digimon in battle, it checks security before the attack ends.)
Lv.4 Vegiemon BT22-049 U champion | Virus | Carnivorous Plant/DM/Ver.2 [Digivolve] Lv.3 w/[DM] trait: Cost 3 [End of Your Turn] [Once Per Turn] By placing 3 Digimon cards with the [Ver.2] trait from your trash face down as this Digimon's bottom digivolution cards, it may digivolve into a Digimon card with the [Ver.2] trait in the hand or trash. --- <Piercing> (When this Digimon attacks and deletes an opponent's Digimon, it performs any security checks it normally would.)
Lv.4 ベジーモン BT22-049 U 成熟期 | ウィルス種 | 食虫植物型/DM/Ver.2 【自分のターン終了時】[ターンに1回]自分のトラッシュから、特徴に「Ver.2」を持つデジモンカード3枚をこのデジモンの進化元の下に裏向きで置くことで、このデジモンを手札/トラッシュの特徴に「Ver.2」を持つデジモンカードに進化できる。 --- ≪貫通≫(このデジモンがアタックしたバトルで相手のデジモンを消滅させたとき、アタック終了前にチェックする)