I read that a Uttama Guru gets all the sins from His devotees the moment He blesses them. Is there anything that a devotee can do on his behalf to reduce Guru’s sufferings?

The only act a true devotee can do is to chant Nama to express the gratitude to the Guru for the grace showered on the devotee.

Which among the following is the easiest way for liberation? Guru Bhakti, Bhagavat Bhakti or building and renovating temples?

If you get a proper Guru (‘Uttama Guru’), then Guru Bhakti is the easiest way
Here are a few of numerous reasons why such a Guru Bhakti is supreme:
You can see your Guru as you see anyone else.
You can talk to your Guru as you talk to anyone else
The Guru is easily approachable
The Guru can get his ideas clearly across to you
The Guru will battle with you to make you good
God Himself says that its verily God who comes in the form of the Guru to liberate masses.
The Guru never expects anything else from you but for your love
You can visit his place and enjoy bliss and peace
The Guru can visit your place too.
The Guru will never destroy or curse anybody (even God could kill a Kamsa or a Ravana, but the Guru’s compassion is boundless)
Instead of cursing bad people, the Guru will transform them to godliness
The Guru will remove your obstacles in the divine path — both internal and external.
The Guru is the only person in the world who can do something good to you without any reason
The very sight of your Guru will help you develop your faith in God.
Scriptures say that your Soul, God and the Guru are one and the same.

Great Mahans speak a lot about surrendering oneself to a perfect Guru; to someone who can accept the surrender and not run away, but stand and protect him. How important is the choice of the right Guru, especially in this Kali Yuga? How does one identify the right Guru?

Let us assume that someone wishes to do a particular task very badly and needs help. His dearest friend who is alongside is not in a position to help him do that task because of various reasons. What would the ideal friend do? Would he not put his friend in touch with someone capable and ready to help him out?
In the same way, if you are really in dire need of a Guru and sincerely long for one, the most lovable Lord Krishna will put you in touch with a Uttama Guru who can quench your thirst. You do not need to identify a guru yourself. If the longing is real, deep inside your heart, the Guru will identify you by himself. This is true for any Yuga.

Can one get salvation only though a Sadguru who is present in physical body?

That is not the only way. But it is one of the easier paths.

What happens to a person who in their lifetime has not been graced with the shelter of a Guru (Sadguru) and in their final moments utters Rama Nama or hears Rama Nama? Do they still attain the Divine Abode of Sri Hari?

Yes. The Ajamila Charitra describes just this. So it is true. But it is very difficult.

I want to have a Sadguru – but Who? When? Where? Who should I choose as my Sadguru?

The human life is said to be the greatest gift of God. In this life, getting the quest for God and the need for a Sadguru is indeed even more rare. When your quest is real, the Lord will automatically bless you with a Sadguru at the right moment. Until then, keep chanting the Mahamantra constantly, taking the Almighty as your Guru. You will soon be blessed with a guru.

I just love God and my Guru. But some say that one should fear God. I dont get any fear on either. converse with them as I would, to my most lovable friend. Am I doing something wrong? Should I fear them?

There is a beautiful word in English – ‘AWE’. Kindly look up the meaning in the dictionary. That is exactly the feeling that we should develop for God and the Guru.

What is the difference between a mother and a Guru?

Although mother’s love is supreme, it is only human. Guru’s love is divine.

I have heard that there are two types of Gurus – ‘Niyat’ (who makes you understands your True Self) and ‘Aniyat’ (who leads you to prayer and worship). Which kind of Guru should one follow?

Prayers and worship eventually lead one to the Realization of your True Self Hence one should follow both kinds of Gurus, in that order

If a person’s life is according to his poorva vasana/destiny, How can a guru help him?

We may have taken thousands of births and committed millions of sins. No matter how colossal that figure maybe, it is unquestionably well within the realm of the finite. Guru’s boundless grace though, is immeasurable, limitless and infinite.
The tapas and grace of the Sadguru can make up for his Karmas and takes him to the path of liberation quicker.