A lot of Questions

Hi guys !
First, i would like to apologize for my bad english, because i'm brazilian.   
I play SSO a long time, but have somethings that i don't know.
Ok, let's go to the questions.

1 - What's the best equipment to use the 100% blood?
I think it's Pants or Shirts, because of the HP add on.

2 - How to unlock the 2 last stones on the "Artifact System"?
Even levelling the 3 first stones, the 2 last still unlock

3 - Is interisting level up the "Planet System" to lvl 25?
I know that system in this lvl give new "Wings", but the stats are good?

4 - What's the lvl 20 Siren Skill? It's a Passive (Like the gold cloths, that have a % to active)? It is intersting have a Siren cloth?
I heard that their skill is healing.

5 - What's the  blood used on lvl 102 Surplices? It's the same as T3 and T4 Silver cloths?

6 - There's one way do unlock equipped "Yellow Itens"? Or once used, there's no way to unlock?]

7 - The 3 Kyotos surplices are good? There's any advantage in using it?
I know whn you die, you can respawn with the Surplice and make a great damage with skills.

8 - What's gold cloth gave more hp when unequipped?
I think it's "Water Cloths", am i right?

9 - When the new "Soul System" have all slots unlocked?
I'm lvl 94 and still 2 more slots in each part.

10 - There is a chance of the Book that costs 2000 points on guild base give a Silver Cloth permission? Or the book of 4000 points have more chance?

11 - What's the max level of passive skills (elemental defense)?
I heard that it's lvl 25.

12 - It's interesting level up the pasive skills that costs player cash? If, what's the best lvl to my primary element skill and secundary element skill?

13 - What's the "Guild Buff" that people say?

14 - What's that item who sell in the guild city, that costs a lot of player cash?

That's all.
Again, i apologize for my bad english.
Thanks !

1- You can;t use only HP items
3- sure every lvl up you getting better stats.
5- No, you can buy purple blood from the NPC
6- Probably no.
7- Yes they can be +48 like starter cloth, stats you can see in cloth emulator.
8- All clothes give you stats when they are "unequipped" when you put it on you getting more stats.
10- Yes, here no 100% chance for get the permission you need luck.
14- If you talk about the potions, they give resistance, fast pick up after KO, etc...

I use 100% on the cape.

Thanks a lot, BadPicollo !