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.

Yes, you can.

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.

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

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

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.

It’s trashed.

No, you can't. For this card's 1st effect, you declare a digivolution, then upon revealing this card, you can also choose a Tamer as the card to digivolve, and that Tamer is also treated as a level 3 Digimon. As with the normal digivolution procedure, after revealing this card and declaring a digivolution, you can't choose to not digivolve. In addition, you can't declare digivolution into this card in the first place unless there is a card on the field that you can digivolve.