Sundara Kanda will be recited in temples and individual houses with a strong belief that it will bring success/mental solace/confidence to the persons reciting them.
It mainly covers the search for Sita by Sri Hanuman, his dejection at not finding Sita, recovery of Sri Hanuman from dejection, the subtle way of his dealing with Sita, the exploits of Sri Hanuman in Lanka, restoring confidence in Sita by the former.
So after reading Sundara Kanda, naturally one will find oneself elated, one's confidence level increases in making efforts towards unfinished/unachieved tasks.
It is true that the other Kandas cover the exploits of Sri Rama over his enemies. However, Sundara Kanda offers something else to the readers.
If one reads carefully one will find that Sri Hanuman did not carry any weapon with him to Lanka. The pictorial depiction of him carrying a mace is imaginary. That indicates his confidence levels. He did not use his Supernatural powers at his whims and fancies to frighten ordinary mortals. He used them only when the situation warranted usage of the same.
Apart from the above apparent stories, some deep SPIRITUAL issues were discussed in the Sundara Kanda, which will be understood only if one studies it in that angle.
I) Sri Hanuman describes Sita to be a disciple of Sri Rama. The established practice of disciple following his/her Guru in all respects, which elevates one SPIRITUALLY and bestows powers, was described by Valmiki in Sundara Kanda.
असंदेशात्तु रामस्य तपसश्चामपालनात् |
न त्वां कुर्मि दशग्रीव भस्म भर्मार्ह तेजसा ||
"O Ravana! Although you are suited to be burnt into ashes, not having the mandate of Rama and preserving austerity, I am not reducing you into ashes with my glory."
(Sundara Kanda 22nd Sarga 20th Sloka)
II) Sage Valmiki describes Sri Hanuman to be follower of Dakshinachara, the follower of Vedic way of life.
अञ्जलिं प्राङ्मुखः कृत्वा पवनायात्मयोओनयो |
ततो हि ववृधे गन्तुं दक्षिणो दक्षिणां दिश्म् ||
(Sundara Kanda 1 Sarga 9 sloka)
Hanuman turned towards east, saluted his father, the Lord of Wind and increased his body to go towards southern direction.
Sage Valmiki used the words दक्षिणो दक्षिणां दिश्म् in the sloka. If the words दक्षिणां दिश्म् indicate Southern Direction, why did the sage used the word दक्षिणो (Dakshino) again?
Did he use without any purpose?
I have gone through many translations, but almost all the translators, except (Late) Sri Gunturu Seshendra Sarma, did not give explanation to the word दक्षिणो (dakshino).
(Late) Sri Gunturu Seshendra Sarma in his literary work "SHODASI - Ramayana Rahasyalu (Telugu)" give the following explanation for the word दक्षिणो (dakshino).
The word दक्षिणो (Dakshino) was used to indicate that Sri Hanuma is the follower of DAKSHINAACHARA, i.e., the VEDIC way life.
Dakshinachara means, in my view, not only following the way of life, but reaching the highest point in the life, ie., reaching the pinnacle of SPIRITUAL PATH, and consequently becoming a REALISED SOUL, or Jnani.
A REALISED SOUL, or Jnani, may or may not attain Super Human Powers, depending upon the Prarabdha of that body.
If we observe the lives of modern saints of our era like Sri Shirdi Sai or Sri Ramana Maharshi, etc, we can understand that Sri Shirdi Sai and Sri Ramana Maharshi were both REALISED SOULs, or Jnanis.
However, Sri Shirdi Sai exhibited Super Human Powers, whereas Sri Ramana Maharshi did not exhibit Super Human Powers, just because it is the Prarabdha of the respective bodies.
Sri Hanuman was a learned person, carried enormous strength, exhibited Super Human Powers, apart from being a Realised Soul.
Sage Valmiki presented Sri Hanuma as the representative of Dakshinachara, whereas Ravana and Indrajit was presented as the representatives of Vamachara.
Was Tantric upasana (Vamachara) a relatively new concept (or) in existence in ancient India also?