How can yoga be a system of spiritual development?
Body & mind are inextricably linked so before you can tackle any work with the mind & consciousness you need to start on the body.
A healthy body produces a healthy mind. Health of body is established on 3 pillars: #yoga
Exercise: Includes cardio-vascular like walking, cycling, jogging, tennis, squash as well as retaining full range of motion and flexibility as well as improving strength through āsana
A classic example is Swami Vivekanand, disciple of Shri Ramakrishna Paramahams.
I am the disciple of a man who could not write his own name, and I am not worthy to undo his shoes. How often have I wished I could take my intellect & throw it into the Ganges!
Swami Vivekananda
If Guru here means one adept in Spiritual knowledge but not Self-realized, then yes.
Such a Guru will be proud of his disciple, encourage him/her to move further, even send him/her to other Masters.
One may rarely attain all of Guru's teachings & still be moving further
How important is the study of Sanskrit for a serious student of Classical Yoga or Vedanta? Is it crucial to the correct understanding of the philosophy, or is that time better spent in other practices (e.g. meditation)?
Sanskrit grammar and syntax is not important; a deep and extensive knowledge of certain roots and technical terms is essential since many of the terms are multivalent and can mean different things in different contexts.
Translating Hindu philosophical terms with Christian equivalents is woefully misleading. For example the following concepts are inadequately rendered by their commonly used English translations:
How do you reconcile 'you are already enlightened and there's no need to strive!' with 'you should strive for enlightenment. Purify your mind!' (Enlightenment, truth, Buddhism)?
The confusion is because of the wrong word called enlightenment.
There are beautiful Mahavakyas in Sanskrit pointing to this- Ekam Brahma- Brahman is One, Aham Brahmasmi- The inside is of the nature of Brahman, TatVamAsi- You Are That, and so on.
Don't you agree that if there was more than one God in the universe then they sure would have fought each other for complete dominance in the universe, resulting in its destruction?
(This seems to be a theistic geo-centric point of view.)
The Zoroastrians believe that there is a good God - Ahura Mazda, and an evil God (Ahriman) who would fight each other for control of the world - Ahura Mazda will ultimately win.
Some Abrahamic faiths believe that God will fight the Devil/ Satan/ Leviathan in end of days & triumph. The Gnostics believed that an evil God (The Demiurge) had created this world & entrapped the souls & that the good God Jesus would liberate all souls from it.
Ketu is 7 years,
Venus 20 years
Sun is 6 years.
Moon 10 years,
Mars 7 years,
Rahu is 18 years,
Jupiter is 16 years,
Saturn is 19 years,
Mercury 17 years, ie-
7+20+6+10+7+18+16+19+17