My very dear one,
Thank you very much for your kind letter, sorry for the long delay in replying.

Regarding your question about the ten qualities of a guru—there are ten outer qualities according to lower tantra and ten inner qualities according to highest tantra. You can find these in the Guru Puja and in lamrim commentaries (Liberation in the Palm of Your Hand, Lamrim Chenmo, etc.). It is very good if you read these and study this well. Also, you can find it in the commentary on 50 Verses of Guru Devotion.

There are qualities that the guru should have and qualities that the disciple should have. The minimum qualities the guru should have are having the lineage of the initiation (that he is giving) and living according to samaya vows and tantric vows, and that the deities have not prohibited him from offering the initiation by giving signs, for example.

You can read and study the section in the Guru Puja that covers the qualities of the guru (before the section which begins “you are my Guru, you are my Yidam …..”

First it mentions the ten qualities of a Mahayana Guru:

1. Discipline as a result of his mastery of the training in the higher discipline of moral self-control;
2. Mental quiescence from his training in higher concentration;
3. Pacification of all delusions and obstacles from his training in higher wisdom;
4. More knowledge than his disciple in the subject to be taught;
5. Enthusiastic perseverance and joy in teaching;
6. A treasury of scriptural knowledge;
7. Insight into and understanding of emptiness;
8. Skill in presenting the teachings;
9. Great compassion; and
10. No reluctance to teach and work for his disciples regardless of their level of intelligence.

Even if one doesn’t have all the ten qualities but has five, six, or seven qualities, the main quality is having more knowledge than the disciple and having great compassion.

A tantric master must have even more good qualities. Most important is that he be an extremely stable person, with his body, speech, and mind totally under control. He should be someone in whose presence everyone feels calm, peaceful, and relaxed and even the mere sight of him brings great pleasure to the mind. And his compassion must be unsurpassable.

There are two sets of ten fields in which the vajra guru must be a complete master. The ten inner ones are essential for teaching the yoga and maha-anuttara yoga classes of tantra, which stress the importance of purifying mainly internal mental activities. These are expertise in:

1. Visualizing wheels of protection and eliminating obstacles;
2. Preparing and consecrating protection knots and amulets to be worn around the neck;
3. Conferring the vase and secret initiations, planting the seeds for attaining a buddha’s form bodies;
4. Conferring the wisdom and word initiations, planting the seeds for attaining a buddha’s wisdom bodies;
5. Separating the enemies of Dharma from their own protectors;
6. Making the offerings, such as of sculptured tormas;
7. Reciting mantras, both verbally and mentally, that is, visualizing them revolving around his heart;
8. Performing wrathful ritual procedures for forcefully catching the attention of the meditational deities and protectors;
9. Consecrating images and statues; and
10. Making mandala offerings, performing the meditational practices (sadhana) and taking self initiations.

The ten external qualities are required for teaching the kriya and charya classes of tantra, which stress the importance of purifying mainly external activities in connection with internal mental processes. These are expertise in:

1. Drawing, constructing and visualizing the mandala abodes of the meditational deities;
2. Maintaining the different states of single-minded concentration;
3. Executing the hand gestures (mudras);
4. Performing the ritual dances;
5. Sitting in the full meditation position;
6. Reciting what is appropriate to these two classes of tantra;
7. Making fire offerings;
8. Making the various other offerings;
9. Performing the rituals of: 
   a) Pacification of disputes, famine, and disease,
   b) Increase of life span, knowledge, and wealth,
   c) Power to influence others and
   d) Wrathful elimination of demonic forces and interferences; and
10. Invoking meditational deities and dissolving them back into their appropriate places.

Lama Tsongkhapa explained that in degenerated times it is difficult to find lamas having all these qualities mentioned above, so if the lama does not have all those qualities then having two, five, or even eight is sufficient.

As I mentioned before, the minimum qualities the guru should have is having the lineage of the initiation (that he is giving), living according to samaya vows and tantric vows, and that the deities have not prohibited him from offering the initiation by, for example, giving signs, etc.

Since you have received highest tantra initiation from Denma Locho Rinpoche, this means he is your guru. Any time that you take a teaching with the recognition that you are the disciple and the teacher is the guru, then even if the teacher only says a few words, a verse of teachings, or one mantra recitation, that person is your guru from then on and there is no change. After one makes that Dharma connection of guru and disciple, then if you give up it is the heaviest negative karma, the greatest obstacle to your spiritual growth. It brings heavy obstacles and one has to experience, especially at the time of death, eons of suffering in the lower realms and hell realms.

According to the texts, the teachings of the Buddha, the lamrim, one is supposed to think only of the qualities of the guru and only praise them. The heaviest negative karma is if anger and heresy arise, and you criticize him or her.

It is said in many tantric teachings—the Kalachakra and Guhyasamaja—that even if one has accumulated the five uninterrupted negative karmas, one can still achieve the sublime vehicle in this life, in particular the maha-anuttara path. This path has the most skills to grant enlightenment in a brief lifetime of these degenerate times. But if you criticize the guru from the heart, even if you practice the sublime vehicle, you will not achieve this.

In the Lama Tsongkhapa lamrim it is clearly mentioned that even the thought that the virtuous friend is ordinary becomes a cause to lose realizations, which means that it also becomes an obstacle to developing the mind on the path.

The most important thing is to analyze as much as possible before making Dharma contact. When the recognition of guru and disciple is present, since the Dharma contact is established, then from that time there is no change. One has to have a new relationship with the guru, it is another world, looking at that person with a new and pure mind.

It is said by Pabongka Dechen Nyingpo, the great enlightened being, the Heruka, that if one is able to stop all thoughts of mistakes and look only at the qualities of the guru, looking at the guru only as Buddha, then one can achieve enlightenment in this life. With the realization of seeing all buddhas as the guru and all gurus as the Buddha, one can get enlightened. This is mentioned in all four Tibetan Mahayana sects, in both sutra and tantra.

Making mistakes, the arising of heresy, anger, criticism, and giving up the virtuous friend become the cause to not find a guru in future lives. It is said in the Essence of Nectar that one cannot ever hear the sound of the holy Dharma, not to mention find a virtuous friend, and one becomes without a virtuous friend in all one’s lifetimes.

If one's own mistakes seem to appear in the guru’s actions, in one's hallucinatory mind, one must realize that this is one's own mistake and abandon it like poison. One must abandon the thought that there is a mistake in the actions of the virtuous friend. With this mindfulness, one looks at that person as Buddha, as one who has eliminated all mistakes and has all the perfect qualities.

If the guru asks you to do something, and you don't have the capacity to do it at that time, your mind hasn't reached that level, so with this pure thought, with this mindfulness, one respectfully explains to the guru how one is incapable of doing this, and in this way tries to get his or her permission not to do it.

This is what is said in the Fifty Verses of the Guru and the Vinaya. If the guru says to do something that is not Dharma, one can ask also permission not to do it. It doesn’t say in the text to have negative thoughts or to criticize or sue him. This is how you deal with that kind of problem without it becoming an obstacle to developing one's own mind on the path.

Of course, as His Holiness the Dalai Lama mentions all the time, if it is a special guru and disciple relationship, then you do every single thing the guru says, like Tilopa and Naropa, and Marpa and Milarepa, and so forth.

I hope this answers your question. You should study the tantric commentaries from qualified lamas such as His Holiness the Dalai Lama, and, in the future, if you pray, you will also be able to receive direct tantric teachings.

With much love and prayers...