Q1: If I have exactly 3 cards in my security stack, can I activate both the "suspend 1 of your opponent's Digimon or Tamers" effect and the "1 of their Digimon or Tamers can't unsuspend until the end of their turn" effect when activating this card's When Digivolving effect?
Yes, that's correct.
Lv.4 Exermon P-150 P Champion | Data | Insectoid [Digivolve] [Pulsemon]: Cost 2 [When Digivolving] If you have 3 or more security cards, suspend 1 of your opponent's Digimon or Tamers. If you have 3 or fewer, 1 of their Digimon or Tamers can't unsuspend until the end of their turn. --- Inherited: [All Turns] [Once Per Turn] When this Digimon suspends, suspend 1 of your opponent's Digimon with as much or less DP as it.
Lv.4 Exermon P-150 P Champion | Data | Insectoid [Digivolve] [Pulsemon]: Cost 2 [When Digivolving] If you have 3 or more security cards, suspend 1 of your opponent's Digimon or Tamers. If you have 3 or fewer security cards, 1 of your opponent's Digimon or Tamers can't unsuspend until the end of your opponent's turn. --- Inherited: [All Turns] [Once Per Turn] When this Digimon is suspended, suspend 1 of your opponent's Digimon with DP less than or equal to this Digimon's DP.
Lv.4 Exermon P-150 P Champion | Data | Insectoid [Digivolve] [Pulsemon]: Cost 2 [When Digivolving] If you have 3 or more security cards, suspend 1 of your opponent's Digimon or Tamers. If you have 3 or fewer security cards, 1 of your opponent's Digimon or Tamers can't unsuspend until the end of their turn. --- Inherited: [All Turns] [Once Per Turn] When this Digimon becomes suspended, suspend 1 of your opponent's Digimon with DP less than or equal to this Digimon.
Lv.4 エキサモン P-150 P 成熟期 | データ種 | 昆虫型 「パルスモン」:コスト2 【進化時】自分のセキュリティが3枚以上なら、相手のデジモン/テイマー1体をレストさせる。自分のセキュリティが3枚以下なら、相手のターン終了まで、相手のデジモン/テイマー1体はアクティブにならない。 --- Inherited: 【お互いのターン】[ターンに1回]このデジモンがレストしたとき、このデジモンのDP以下の相手のデジモン1体をレストさせる。