​Arcana Ruin Skill Questions in Lost Ark

So I'm able to understand the basic trick of Arcana by stacking four debuffs by using blue skills. Activate Ruin (red) abilities. But I'm not sure how stacks can help.

1. If Ruin stacks are consumed Are they considered to be as [Ruin] damage? In other words, are they amplified by specialization stats, or is it only the base damage of red skills is increased by specifics?

2. Do you think the stack damage is a valid reason as a Crit/Hit Master/Barricade (with the protection rune)? I have seen a lot of guides that recommend these two engravings, and I want to ensure that I know the rules instead of following them in blind faith.

Serendipity-related answers.

3. Lucky Blow So, with 4 stacks, there could be an 88% chance of having greater critical damage. If Intended Luck is true, is that 100%? If not, could someone explain Intended Luck Tripod. I'm not sure if it's the translation or my English sorry.

Secret Garden question...

4. Secret Chance tripod indicates Ruin Damage incoming. Do you think that means damage to the stack, Secret Garden damage, or both? It's also the only skill I've seen that specifically refers to players. I'm not a player in PvP. Does this mean that this skill is not a good match for charming players like Vykas? Why is that?

5. Vital Point Hit tripod has +15percent. I'm assuming this isn't the identical to the Lucky Blow tripod from Serendipity so regardless of how many stacks you own it will always be a boost of 15?

I'm sorry if this was not clarified in the game. I could not find any information within the game as I perused the codex/training area. And the cheapest Lost Ark gold at p2pah shop deal, fast delivery & 100% safe service.