Whatever you do will certainly have their effects. Unless you are a Gayatri-upasak, you should not chant the Gayatri Mantra as and when you wish. You can chant it as many times as you wish with proper purity, and following the appropriate guidelines prescribed for it in our Scriptures.
JAPA
I read somewhere that it is an offense to preach the glories of the holy name of the Lord to the faithless. Then what is the way to get the faithless to chant?
There are scriptures. The same scriptures also state that one should follow the words of the Guru without any doubts or questions and act accordingly. Going by that rule, all our masters starting from Chaitanya Mahaprabhu are crying aloud to make the people chant the Holy Name to have them liberated! So we take that path.
Every rule has an exception too!
What are the do’s and don’ts to perform Japa of the mantra given by the Guru? Can it be chanted all times, irrespective of the location and dress code (i.e. in office attire wearing shoes etc.)?
The “Rama” Nama and Mahamantra have no rules. You can chant it any number of times, any place, any time of the day and in any state.
Other mantras may have their own restrictions and have to be chanted as instructed by the Guru.
I have heard that it is necessary to have a Guru initiate one into the Mantra, without which chanting of any mantra is futile. How true is it?
For any mantra, a Guru is a must. For Rama Nama and the Mahamantra, you can start chanting even without a Guru. When you are accepted by a Guru, you can take formal initiation from him and continue. For all other mantras, one can recite it only after proper initiation.
When I chant any Mantra, some thoughts run in the back of my mind simultaneously. The moment I realize this happening, the thoughts cease and Japa seems to resume. Now, who is chanting the Mantra and who gets the thoughts? Are both one and the same person?
When the force of air is mild, we call it breeze. When it blows with great force, we call it a storm. In the same way, when the mind imagines, it is called ‘manas’. When it thinks, it is called ‘intellect’.
It is the same person who chants the Mantra as well as gets those thoughts. The phenomenon that you experience is because of the fact that the mind operates at different levels.
It is also the same reason why people perform acts like ‘ashtavadanam’ (performing eight non-connected activities at the same time) etc.
Is both meditation upon self and chanting the name of Krishna/Rama or Ganesha produce the same effect?
Chanting continuously in the mind, without a gap of even a microsecond – that is meditation.
Can we chant mantras like ‘Om Namo Narayana’ etc. in the place of Maha Mantra? What impact does it make on our spiritual life?
You can chant any Divine Name of the Lord.
Each Mantra has its own merits and demerits The Maha Mantra has been prescribed in the Shastras as t he means of liberation in this Yuga.
When you chant a mantra, it reverberates with the cosmic and energizes it.
Many Mahans and saints including Sri Chaitanya Maha Prabhu and all his devotees have chanted the Maha Mantra and are still chanting it till date, all over the world. Hence the cosmic is filled with the power of this Name. Thus, by chanting this Mantra, one gets to see the results very soon.
In addition to being a Mantra, this is also a Nama. So, there are absolutely no restrictions to chant this Nama.
That is why Maha Mantra is advocated for liberation.
From whom can one take initiation? Is initiation taken only after marriage?
Initiation should be taken from someone who has attained siddhi in that particular mantra. There is no relationship between initiation and marriage.
Sometimes I start chanting or writing the Mantras without taking bath. Is this allowed? How do I quit this habit?
If you are chanting the Mahamantra, it is harmless. You are not allowed to chant the other Mantras without taking bath. Instead of changing your bathing habit, change over to the Mahamantra. That will prove good for you.
Is chanting while doing work considered as meaningful chanting ? Since most of the days , I am continuously doing house chores one after the other, I don’t get time to sit and do ‘Japa’. But if we chant while doing house chores, does it have same effect ?
Yes. It is definitely great. The Gopis did exactly that way.
