Q1: What order do an effect that triggers when a card is removed from a security stack and a Security effect on a checked card activate when they trigger simultaneously upon a security check?
The Security effect will activate first. Upon a security check, a Security effect will immediately activate without pending activation.
Q3: This card attacks and I perform a security check on my opponent. If I then use this card's Your Turn effect to digivolve into a Digimon card with Security Attack +1, is another security check performed?
Yes, another security check is performed.
Lv.4 BurningGreymon BT21-014 C Hybrid | Variable | Dark Dragon [Digivolve] [Agunimon]: Cost 1 [On Play] [When Digivolving] This Digimon gains <Piercing> and +3000 DP for the turn. [Your Turn] When your opponent's security stack is removed from, this Digimon may digivolve into a level 5 Digimon card with the [Hybrid] trait in the hand with the digivolution cost reduced by 1. --- Inherited: [Your Turn] This Digimon gets +2000 DP.
Lv.4 BurningGreymon BT21-014 C Hybrid | Variable | Dark Dragon [Digivolve] [Agunimon]: Cost 1 [On Play] [When Digivolving] This Digimon gains <Piercing> and +3000 DP for the turn. [Your Turn] When your opponent's security stack is removed from, this Digimon may digivolve into a level 5 Digimon card with the [Hybrid] trait in the hand with the digivolution cost reduced by 1. --- Inherited: [Your Turn] This Digimon gets +2000 DP.
Lv.4 BurningGreymon BT21-014 C Hybrid | Variable | Dark Dragon [Digivolve] [Agunimon]: Cost 1 [On Play] [When Digivolving] This Digimon gains <Piercing> and +3000 DP for the turn. [Your Turn] When your opponent's security stack is removed from, this Digimon may digivolve into a level 5 Digimon card with the [Hybrid] trait in the hand with the digivolution cost reduced by 1. --- Inherited: [Your Turn] This Digimon gets +2000 DP.