Q1: If this card has a tamer card as a digivolution card, does the Security effect of that tamer card become an inherited effect?

No, Tamer cards' Security effects aren't inherited effects. Some Tamer cards do have inherited effects, and those can be activated when such cards are placed in digivolution cards.

Q2: Can this card digivolve on top of a Level 3 Digimon that meets its requirements instead of a tamer card?

Yes, it can.

Q3: If I use this card's effect to make a tamer card into a digivolution card, is that card affected by effects that say "trash digivolution cards"?

Yes, it is. However, if the effect specifies Digimon cards, Digi-Egg cards, or any other type of card that isn't a tamer card, it can't be targeted by that effect.

Q4: If I digivolve this card on top of a tamer card, do I still get the digivolution bonus?

Yes, you do. Even if you digivolve using a tamer card, make sure to draw 1 card as the digivolution bonus.

Q5: Can I attack the turn I digivolve this card on top of a tamer card?

Yes. Digivolution doesn't count as playing, so you can attack that turn.

Q6: Can I attack the turn I played a tamer card if I then digivolve this card on top of it?

No. Since it's the first turn the tamer was played, the limitation for attacking on the first turn a card is played still applies.

Q7: If I've digivolved this card on top of a tamer card and the Digimon is deleted, what happens to the tamer card?

It is trashed.