The Ari over the Ramak

 Kabalah. There are serious problems involved in learning it. The Ari himself warns that one who is not properly prepared, Kabalah kills them--spiritually. [That statemnt is in Parshat Haazinu]. [And the Ari repeats this warning  a few places].  That means: they enter into the Intermediate Zone and think they have reached great spiritual heights, when really they have sunken deeply into a world illusion. And who am I to argue with Isaac Luria?
So learning Kabalah at all should be short and sweet.--if at all.
And if you do learn it at least make sure it is authentic.

Kabalah in the Ashkenazic world after 1700's  got thematic material from Shabati Tzvi. Plus most Ashkenazic interpretations of the Ari are all derived from Natan the false prophet of the Shatz.

So my recommendation when it comes to Kabbalah is to learn one or all three of these schools of thought: 1) Reshash (Shalom Sharabi) --in Jerusalem that would be the yeshiva, Shaar Hashamayim of Mordechai Sharabi. 2) Yaakov Abuchatzeira --in Israel that would be David Abuchatzeira in Nahariya. 3) Moshe Luzzatto.

You could do this on your own if you are not in Israel. The Kabbalah Center in Israel has a great edition of the Ari, with Shalom Sharabi's book in the back of the Eitz Chaim and the notes of the disciple of the Ashlag. And that is a very good place to start.
As for what people are looking for authentic kabbalists or mystics-- I think many descendants of Bava Sali [maybe all] have some degree of the Divine Spirit because of some kind of merit that he must have had.
In Netivot, I was very impressed with Shimon Buso, a grandson of Bava Sali from the side of his mother. If authentic mystics is what you are looking for, that is probably the first place I would start.--and his mother also -the daughter of Bava Sali Avigail Buso.

But outside of that Abuchatzeira  family, I would avoid mystics. Most are heavily into the Intermediate Zone, and drag their followers down into the bowels of hell with them. I see this all the time.

In the thought of Isaac Luria the way the world was created was this

 In the thought of Isaac Luria the way the world was created was this: (step 1) The light of God is everywhere and thus no place for creation. (step 2) He withdraws himself from a certain area to create an empty space ("the Halal Hapanui"). (step 3) Then He sends down his light into that space; first as 10 circles [concentric spheres like an onion], and then in the form of a human being (Adam Kadmon), mentioned by Hegel.  (Step 4) Then the light comes down from Adam Kadmon to make the world of "Nekudim". (step 5) Shevirat Hakelim breaking of the vessels of Nekudim. (step 6) Bringing up the broken vessels and bringing down the light of the Divine name 45 to create the world of Emanation. (step 7) Ditto for the world of Creation, Formation and then the Physical Universe.

[This is based mainly on the verses of the Old Testament about the kings of Edom mentioned in Genesis.]

The main place to learn this is in the עץ חיים or מבוא שערים.

[I should mention that the Gra held highly with the Ari.]

The major thing to learn in the Ari is the Tree of Life.  In terms of the intentions I have found the best thing is the large sidur of the grandson of the Reshash. If one does not have that, then the best in the small set of the Sidur HaReshash. Both are good but the large sidur is more thorough. [The small one is actually a version not directly from the Reshash himself.]  

The Rambam posits a system of a priori values that the mitzvoth are to bring to.

Learning Rambam is not claiming he had absolute truth.
It is searching to truth and justice. The Rambam posits a system of a priori values that the mitzvas are to bring to. [The Sefer Hachinuch brings them on each commandment] Certainly you will admit that is already an improvement on judicial activism of Supreme Court judges that think that if they say something that makes it moral and obligatory for people to listen to them. 

But there are books on a secondary level that are needed to find the depth of the first level books--for instance Aristotle I think is necessary to understand Plato. Some later people are important to understand Kant.

So an author like Reb Chayim HaLevi is important to understand the depth of a first level person like Maimonides. For example most people open up a Rambam and don’t see any problem at all. (They never get past the superficial level.)

What happens when you read book is your stream of consciousness is focused into what the book is saying. And if it is bad it can affect you badly. And some of it might even seep into your sub level subconscious]

I think most problems in the  world comes from a blurring of the distinction between
 books and great  books.
I mean there are  Jewish books that are not great. Even bad. [What happens when you read book is your stream of consciousness is focused into what the book is saying. And if it is bad it can affect you badly. And some of it might even seep into your sub level subconscious]



My orientation is as a Rationalist. But that does not cancel out the fact that I believe knowledge is available by non rational non perceptive means.
I have great respect for the Ari (Isaac Luria)and Rambam
The general rule of thumb I would like to suggest is that people learn the great books of Torah that are original, fresh, powerful, i.e. The Torah, Talmud (Gemara, Rashi, Tosphot).

The more spirit the less form

The more spirit the less form. Content increases as form lessens. In total form (logic) each sentence has no content (the sentences of logic are just A, B, C and you can fill them with anything) then science has more content but less formal logic behind it. Then morality and ethics has even more content (people and the meaning of life) the God is beyond logical form (even the impossible is possible) but total content. So in this context I would say that the religious world in as much as it stresses halacha [law] loses spiritual content

Rational Approach to the Torah [Maimonides]

I wrote only a short note before about my personal experience. I wanted to leave my answer out of it. But I do have an answer. I believe that the Rambam's rational approach to Judaism holds the key. In the way of thinking of the Rambam's [Maimonides] Reason (i.e. Aristotle's Logic and Metaphysics) and Torah are one organic whole. I think where Judaism (Yidishkeit) went wrong was when this Rambam approach was rejected. (One example of the way of thought of the Rambam is the parable of the King in the Guide for the Perplexed.) In this parable there is a king with a country. People outside the country are barbarians. People in the country are goyim with civilization. People near the palace of the king are Talmudic scholars that know and keep the whole Torah. People in palace are natural scientists. People with the King (God) are the philosophers and prophets.
You can see this approach also in Saadia Geon and the Chovot Levavot [a medieval book on ethics, Duties of the Heart].
This rational approach to Torah was wide spread during the Middle Ages. I think after the time of the Rambam,Yidishkeit deteriorated into fanaticism.
The "Middle Ages" were the age of reason. You almost can never punch a hole in an argument of a medieval philosopher whether Anselm or Maimonides or Aquinas. The characteristic of the great Mediaeval thinkers was that every counter argument against them can usually shows the shallow thinking of the one trying to find the hole. Later thinkers never approach that degree of rigorous thought--ever-- even Kant. 
 The greatness of the Renaissance was in art and in the beginning of empirical thought-not reason

a priori values

A priori values. Freedom and Reason. Sometimes there comes a person into the world whose purpose is to reveal some a priori value.
Or President Kennedy bringing the idea of jogging into national consciousness.
The Rambam also discovered the value of the fusion of Torah with reason.
But with every value that is revealed there is a false value which surrounds it. And there are "chevra mans" that pretend to be supporting the true value, but enforce the false value.
(Just like the idea of freedom got perverted in America to mean the welfare state--the right not be to be insulted, the right to feel good etc.)
The truth be told, we need a process by which good values can be separated from bad values.
To reveal the combination of all good values, that can't happen until one discovers the process by which bad values can be sifted out.
I believe that there is a minimum requirement for a moral value system--that it should be logically deducible from it that murder, rape, and torture of 10 million people is wrong.  Neither does Islam fulfill that requirement. But if you would take the Talmud along with Maimonides who says that the mitzvoth have a priori rational basis under them that determines how the halacha is applied, then Torah and Talmud could be part of a moral system. But only in connection with this idea of Maimonides. Without  him, the Torah could be  as vicious and evil as Islam.