BT26-089 Kyo Sawashiro

If I use this card's [Start of Your Main Phase] effect to place a card under a Tamer with cards under it, in what order do I place the card?

Can I change the stacking order of face-down cards under a Tamer?

Can I search/look at face-down cards under a Tamer?

What happens if a face-down card under a Tamer is trashed?

Can I process the part of the effect after "after" in this card's [All Turns] effect without meeting the "by" condition?

When performing a security check, if a [Security] effect, a "when this Digimon checks an opponent's security" effect, and a "when a security stack is removed from" effect trigger simultaneously, what order do they activate in?