Hi Selim,
You're very welcome. To answer your questions … I'm fairly knowledgeable about Persian literature and comprehension but I wasn't raised there so I will offer this answer consciously and ask that you research it further.
1. Ghalandar is a state of being very similar to the Kalender’s meaning as you stated above. It’s very similar to monks’ life style (minus the martial arts knowledge and the fact that they were said to be semi-drunk most of the time). Ghalandars are also known to shave their heads and give up all their earthly belongings and embark on a journey of self-discovery. The word is not commonly used in conversational Farsi (Persian) but it is a huge complement to call someone “Ghalandar”. It stands for selflessness, spirituality, self-sacrifice, gentleness, and humility.
2. This song can most definitely be a song of Darvish. In the story of Layla and Majnun, he fell in love with Layla and (as is the case for those in love) saw her as his goddess and savior but when he asked for her hand in marriage her father refused and forced her to marry another man. Majnun lost his mind and wandered the desert reciting poetry to himself until he was “reunited” with her in death. Darvish are said to have a bit of “madness” in them (my guess is from drinking booze and smoking something or other with hallucinatory effects) and they are said to be godly and spiritual, thus the parallel to being in love and a bit crazy with whom you worship and not being able to unite until death.
3. It would make A LOT MORE sense if the lyrics were reading “hala” instead of “hana”. The meaning would change to “now, now drunk as Ghalandar” or loosely translated “now I’m in the same state of mind as a Ghalandar.”
I hope this was helpful to you.
Here's another famous song by Dariush called Ghalandar.
http://www.semital.com/g.htm?id=7892